This file was created by the TYPO3 extension publications --- Timezone: CEST Creation date: 2026-06-03 Creation time: 09:49:05 --- Number of references 134 article Haberland2023 We apply a transdimensional, hierarchical Markov chain Monte Carlo sampling algorithm (McMC) for 2-D cross-hole travel-time tomography in transversely isotropic media with vertical symmetry axis. The McMC approach has several advantages compared to classical inversion approaches: It is a global search, the high number of tested models allows the statistical analysis including the calculation of a reference model as well as uncertainty estimation, no initial models or regularization parameters are needed, the amount of data noise is automatically determined, and the model parametrization is data dependent and self-adjusting. For the forward solution a FD Fast Marching method utilizing second-order Godunov schemes is used. The performance of the approach is first tested on synthetic datasets to evaluate the potential and possible limitation to recover anisotropic models. We have shown that the recovery of models described by 2 anisotropic parameters (Thomsen parameters) and the vertical velocity is possible for observation scenarios with good distribution of sources and receivers. For more realistic observational geometries (i.e. cross-hole experiments), the recovery of the 3 parameters is limited, but still possible for example for the elliptical anisotropic case (ε = δ) or regarding the horizontal velocity. Finally we applied the McMC approach to a well-studied real cross-hole data set from the MALLIK 2002 research program and compared the results with previous conventional inversions. © 2022 2023 English 09269851 10.1016/j.jappgeo.2022.104917 Journal of Applied Geophysics 209 Elsevier B.V. Helmholtz Centre Potsdam GFZ German Research Centre for Geosciences, Potsdam, Germany; University of Helsinki, Helsinki, Finland Gas hydrates; Markov processes; Monte Carlo methods; Recovery; Seismology; Uncertainty analysis, Algorithm approaches; Bayesian; Cross hole; Finite difference; Markov chain monte carlo samplings; Monte carlo; Monte carlo sampling algorithms; Seismic; Transversal isotropy; Transversely isotropic medias, Anisotropy, algorithm; Bayesian analysis; data inversion; data set; finite difference method; gas hydrate; Markov chain; model test; Monte Carlo analysis; seismic tomography; seismic velocity; seismic wave; transverse isotropy; travel time https://www.scopus.com/inward/record.uri?eid=2-s2.0-85145773441&doi=10.1016%2fj.jappgeo.2022.104917&partnerID=40&md5=bd4779a5a71010167f3075da54d14613 cited By 0 C. Haberland T. Ryberg M. Riedel K. Bauer article Li2022 The Mackenzie Delta (MD) is a permafrost-bearing region along the coasts of the Canadian Arctic which exhibits high sub-permafrost gas hydrate (GH) reserves. The GH occurring at the Mallik site in the MD is dominated by thermogenic methane (CH4), which migrated from deep conventional hydrocarbon reservoirs, very likely through the present fault systems. Therefore, it is assumed that fluid flow transports dissolved CH4 upward and out of the deeper overpressurized reservoirs via the existing polygonal fault system and then forms the GH accumulations in the Kugmallit–Mackenzie Bay Sequences. We investigate the feasibility of this mechanism with a thermo– hydraulic–chemical numerical model, representing a cross section of the Mallik site. We present the first simulations that consider permafrost formation and thawing, as well as the formation of GH accumulations sourced from the upward migrating CH4-rich formation fluid. The simulation results show that temperature distribution, as well as the thickness and base of the ice-bearing permafrost are consistent with corresponding field observations. The primary driver for the spatial GH distribution is the permeability of the host sediments. Thus, the hypothesis on GH formation by dissolved CH4 originating from deeper geological reservoirs is successfully validated. Furthermore, our results demonstrate that the permafrost has been substantially heated to 0.8–1.3 °C, triggered by the global temperature increase of about 0.44 °C and further enhanced by the Arctic Amplification effect at the Mallik site from the early 1970s to the mid-2000s. © 2022 by the authors. Licensee MDPI, Basel, Switzerland. 2022 English 19961073 10.3390/en15144986 Energies 15 MDPI GFZ German Research Centre for Geosciences, Potsdam, 14473, Germany; Institute of Geosciences, University of Potsdam, Potsdam, 14476, Germany; Institute of Chemistry, University of Potsdam, Potsdam, 14476, Germany 14 Flow of fluids; Gas hydrates; Hydration; Methane; Numerical models; Permafrost; Proven reserves, Canadian Arctic; CH 4; Conventional hydrocarbons; Dissolved CH; Fault; Fault system; Gas hydrates formation; Hydrate accumulations; Mallik; Thermogenic methane, Climate change https://www.scopus.com/inward/record.uri?eid=2-s2.0-85133769521&doi=10.3390%2fen15144986&partnerID=40&md5=52ccd192651a7a678ea2f1fd08041259 cited By 1 Z. Li E. Spangenberg J.M. Schicks T. Kempka article Wu2022992 The bottom simulating reflection (BSR) characteristics of reflected seismic waves are an important sign of gas hydrate. Although they can indicate the bottom of hydrate, they can hardly be used for quantitative interpretation of hydrate content. The rapid development of the gas hydrate exploration technology in recent years results in an understanding that the "blank" zone of seismic amplitude above BSR, directly related to the absorption and attenuation of seismic waves, can be used as an indicator of gas hydrate distribution and quantification. This paper reviews the seismic wave absorption and attenuation characteristics of various hydrate exploration areas around the world (the Mallik permafrost area in Canada, the Nankai Trough in Japan, the Makran accretionary wedge in the Arabian Sea, the Gulf of Mexico, and the Shenhu area in the South China Sea) and artificial hydrate-bearing rock samples. The results show that for different hydrate exploration areas, hydrate-bearing samples, and data used, seismic waves show different attenuation characteristics. Then, the possible attenuation mechanisms and related petrophysical theories are summarized for hydrate reservoirs, mainly including global flow attenuation (the Leclaire model), squirt flow (the improved Leclaire model, the hydrate effective grain (HEG) model for submicron hydrate particle squirt, or the hydrate-bearing effective sediment (HBES) model for micron flow squirt), skeleton friction attenuation (the improved Leclaire model). At present, the main problem is that although the hydrate-bearing strata in many areas demonstrate obvious absorption and attenuation characteristics, the relationships of absorption and attenuation variation with hydrate saturation remain unknown due to the varied hydrate formation conditions and geological environments and different occurrence states of hydrate in sediments of different areas. In addition, the frequency band ranges of the current measured observation data and those petrophysical experiments test are limited, so the characteristics of attenuation variation with frequency are not fully reflected. Therefore, petrophysical experimental studies need to be further conducted, and available data from actual exploration areas and the making and experimental measurement results of artificial cores shall be well utilized, thereby studying the additional effect of the microstructure of the hydrate reservoir on the attenuation mechanism in depth. After the reasons of seismic wave attenuation in hydrate reservoirs are clarified, a quantitative seismic interpretation method for hydrate saturation can be developed. © 2022, Editorial Department OIL GEOPHYSICAL PROSPECTING. All right reserved. 2022 Chinese 10007210 10.13810/j.cnki.issn.1000-7210.2022.04.026 Shiyou Diqiu Wuli Kantan/Oil Geophysical Prospecting 57 Science Press 992-1008 College of Geophysics, China University of Petroleum (Beijing), Beijing, 102249, China 4 Gas hydrates; Gases; Hydration; Microstructure; Petroleum prospecting; Petrophysics; Seismology, Attenuation characteristics; Bottom simulating reflection; Exploration technologies; Gas hydrate reservoir; Hydrate saturation; Petrophysical; Petrophysics; Quantitative interpretation; Reflection characteristics; Seismic attenuation, Seismic waves https://www.scopus.com/inward/record.uri?eid=2-s2.0-85134836876&doi=10.13810%2fj.cnki.issn.1000-7210.2022.04.026&partnerID=40&md5=c2b503cd18422ad74561eea149cc1975 cited By 0 C. Wu F. Zhang X. Li article Lei20222273 Natural gas hydrate (NGH) is a clean and efficient energy resource with extensive distribution in the permafrost regions and marine sediments. A few short-term production tests focusing on reservoir depressurization have been conducted in recent years. However, the long-term production performance and the transient evolution characteristics of reservoir properties are not well known. In this work, a more realistic hydrate-reservoir model that considers the heterogeneity of permeability, porosity and hydrate saturation is constructed, according to the available geological data at the Mallik site. The model is validated by reproducing the field depressurization test. The main purposes of this work are to evaluate the long-term gas production performance and to analyze the unique multiphase flow behaviors from the validated geologically descriptive hydrate-reservoir model. The results indicate that the long-term gas production through depressurization from hydrate reservoirs at the Mallik site is technically feasible, but the gas production efficiency is generally modest. The hydrate dissociation front in HBS is strongly affected by the reservoir heterogeneity and shows a unique dissociation front. The vertically heterogeneous HBS is beneficial for depressurization production compared to the massive hydrate reservoirs. Furthermore, the vertically heterogeneous hydrate-reservoir with low permeability of clay-layer can effectively block methane gas diffusion in the vertical direction. These emphasize that constructing realistic reservoir models is very important to accurately predict the hydrate production performance. At the end of 1-year depressurization, a total of 1.80 × 106 ST m3 of methane gas can be produced from the validated hydrate-reservoir, while which is far from the commercial value. In addition, reducing the production pressure in the wellbore is beneficial for increasing gas production volume, but is not conducive to improving the hydrate production efficiency at the Mallik site. © 2022 The Author(s) 2022 English 23524847 10.1016/j.egyr.2022.01.170 Energy Reports 8 Elsevier Ltd 2273-2287 State Key Laboratory of Geomechanics and Geotechnical Engineering, Institute of Rock and Soil Mechanics, Chinese Academy of Sciences, Wuhan, 430071, China; Hubei Key Laboratory of Geotechnical and Structural Engineering Safety, School of Civil Engineering, Wuhan University, Wuhan 430072, Hubei, China; Key Laboratory of Groundwater Resources and Environment, Ministry of Education, Jilin University, Changchun, 130021, China; Engineering Research Center of Geothermal Resources Development Technology and Equipment, Ministry of Education, Jilin University, Changchun, 130026, China Dissociation; Energy resources; Gases; Hydration; Methane; Natural gas; Natural gas deposits; Petroleum reservoir engineering; Petroleum reservoirs; Submarine geology, Depressurizations; Gas productions; Heterogeneous; Mallik site; Methane gas; Natural gas hydrates; Natural gas-hydrates; Production efficiency; Production performance; Reservoir models, Gas hydrates https://www.scopus.com/inward/record.uri?eid=2-s2.0-85123882564&doi=10.1016%2fj.egyr.2022.01.170&partnerID=40&md5=39876b06a9580d06301a0353839b60a2 cited By 5 H. Lei Z. Yang Y. Xia Y. Yuan article Hinz20227103 A four-phase flow model is developed to capture the unconsolidated flow of gas, water, hydrate, and sand. The solid phase models are an extension of granular flow theory to unconsolidated hydrate-bearing sediment. A solid viscosity constitutive model is developed to model the frictional and cohesive contributions to the solid shear stress. In part 2 of this paper series, the model is validated against the Mallik 2007/2008 production tests. © 2022 American Chemical Society. All rights reserved. 2022 English 08885885 10.1021/acs.iecr.2c00211 Industrial and Engineering Chemistry Research 61 American Chemical Society 7103-7113 ThermoAnalytics Inc., 23440 Airpark Blvd., Calumet, MI 49913, United States; Department of Chemical and Biological Engineering, Wanger Institute for Sustainable Energy Research (WISER), Illinois Institute of Technology, Chicago, IL 60616, United States 20 Confined flow; Gas hydrates; Granular materials; Shear stress, Flow modelling; Four-phase; Gas sands; Gas-water; Granular flows; Methane production; Model development; Phase flow; Phase model; Solid phase models, Hydration https://www.scopus.com/inward/record.uri?eid=2-s2.0-85130744827&doi=10.1021%2facs.iecr.2c00211&partnerID=40&md5=dd0c1202605efbcec2ff7010e1b21c1c cited By 0 D. Hinz H. Arastoopour J. Abbasian article Xia2022434 Natural gas hydrate (NGH) is regarded as an important alternative future energy resource. In recent years, a few short-term production tests have been successfully conducted with both permafrost and marine sediments. However, long-term hydrate production performance and the potential geomechanical problems are not very clear. According to the available geological data at the Mallik site, a more realistic hydrate reservoir model that considers the heterogeneity of porosity, permeability, and hydrate saturation was developed and validated by reproducing the field depressurization test. The coupled multiphase and heat flow and geomechanical response induced by depressurization were fully investigated for long-term gas production from the validated hydrate reservoir model. The results indicate that long-term gas production through depressurization from a vertically heterogeneous hydrate reservoir is technically feasible, but the production efficiency is generally modest, with the low average gas production rate of 4.93 × 103 ST m3/d (ST represents the standard conditions) over a 1-year period. The hydrate dissociation region is significantly affected by the reservoir heterogeneity and reveals a heterogeneous dissociation front in the reservoir. The depressurization production results in significant increase of shear stress and vertical compaction in the hydrate reservoir. The response of shear stress indicates that the potential region of sand migration is mainly in the sand-dominant layer during gas production from the hydraulically heterogeneous hydrate reservoir (e.g., sand layers interbedded with clay layers). The maximum subsidence is approximately 78 mm and occurred at the 72nd day, whereas the final subsidence is slowly dropped to 63 mm after 1-year of depressurization production. The vertical subsidence is greatly dependent on the elastic properties and the permeability anisotropy. In particular, the maximum subsidence increased by approximately 81% when the ratio of permeability anisotropy was set at 5:1. Furthermore, the potential shear failure in the hydrate reservoir is strongly correlated to the in-situ stress state. For the normal fault stress regime, the greater the initial horizontal stress is, the less likely the hydrate reservoir is to undergo shear failure during depressurization production. Copyright © 2022 Society of Petroleum Engineers 2022 English 1086055X 10.2118/206746-PA SPE Journal 27 Society of Petroleum Engineers (SPE) 434-451 Jilin University, China 1 Anisotropy; Dissociation; Energy resources; Gas hydrates; Gases; Hydration; Petroleum deposits; Petroleum reservoir engineering; Shear stress; Submarine geology; Subsidence, Depressurizations; Gas productions; Gas-water; Multiphase gas; Natural gas hydrates; Natural gas-hydrates; Permeability anisotropy; Reservoir models; Shear failure; Water flows, Geomechanics https://www.scopus.com/inward/record.uri?eid=2-s2.0-85126098007&doi=10.2118%2f206746-PA&partnerID=40&md5=3bed2f35089b2fcf344c25532b25725b cited By 3 Y. Xia T. Xu Y. Yuan X. Xin article Chong20221151 Artificial neural network-trained models were used to predict gas hydrate saturation distributions in permafrost-associated deposits in the Eileen Gas Hydrate Trend on the Alaska North Slope (ANS), USA and at the Mallik research site in the Beaufort-Mackenzie Basin, Northwest Territories, Canada. The database of Logging-While-Drilling (LWD) and wireline logs collected at five wells (Mount Elbert, Iġnik Sikumi, and Kuparuk 7–11–12 wells at ANS, plus 2L-38 and 5L-38 wells at the Mallik research site) includes more than 10,000 depth points, which were used for training, validation, and testing the machine learning (ML) models. Data used in training the ML models include the well logs of density, porosity, electrical resistivity, gamma radiation, and acoustic wave velocity measurements. Combinations of two or three out of these five well logs were found to reliably predict the gas hydrate saturation with accuracy varying between 80 and 90% when compared to the gas hydrate saturations derived from Nuclear Magnetic Resonance (NMR)-based technique. The ML models trained on data from three ANS wells achieved high fidelity predictions of gas hydrate saturation at the Mallik site. The results obtained in this study indicate that ML models trained on data from one geological basin can successfully predict key reservoir parameters for permafrost-associated gas hydrate accumulations within another basin. A generalized approach for selecting a well log combination that can improve model accuracy is discussed. Overall, the study outcome supports earlier work demonstrating that ML models trained on non-NMR well logs are a viable alternative to physics-driven methods for predicting gas hydrate saturations. © 2022, The Author(s), under exclusive licence to Springer Nature Switzerland AG. 2022 English 14200597 10.1007/s10596-022-10151-9 Computational Geosciences 26 Springer Science and Business Media Deutschland GmbH 1151-1165 National Energy Technology Laboratory, 626 Cochrans Mill Road, P.O. Box 10940, Pittsburgh, PA 15236, United States; NETL Support Contractor, 626 Cochrans Mill Road, P.O. Box 10940, Pittsburgh, PA 15236, United States; National Energy Technology Laboratory, 3610 Collins Ferry Road, Morgantown, WV 26507, United States; NETL Support Contractor, 3610 Collins Ferry Road, Morgantown, WV 26507, United States; National Energy Technology Laboratory, 1450 Queen Avenue SW, Albany, OR 97321, United States; NETL Support Contractor, 1450 Queen Avenue SW, Albany, OR 97321, United States 5 artificial neural network; gas hydrate; hydrocarbon reservoir; hydrocarbon resource; machine learning; nuclear magnetic resonance, Canada; Mackenzie Delta; Northwest Territories https://www.scopus.com/inward/record.uri?eid=2-s2.0-85132604181&doi=10.1007%2fs10596-022-10151-9&partnerID=40&md5=d44b75dfe2403cdf266d576a0dbf9b6e cited By 1 L. Chong H. Singh C.G. Creason Y. Seol E.M. Myshakin article Hinz20227114 In this paper, the Mallik production tests are simulated using our four-phase flow model for an unconsolidated methane hydrate reservoir. Model development was outlined in part 1 of this paper series. The simulations suggest that the unconsolidated hydrate reservoir with sand production behaves like a naturally fracking reservoir. Solid deformation and the resultant permeability have a substantial effect on the gas production from an unconsolidated hydrate reservoir whether sand is produced or not. © 2022 American Chemical Society. All rights reserved. 2022 English 08885885 10.1021/acs.iecr.2c00212 Industrial and Engineering Chemistry Research 61 American Chemical Society 7114-7129 ThermoAnalytics Inc., 23440 Airpark Blvd., Calumet, MI 49913, United States; Department of Chemical and Biological Engineering, Wanger Institute for Sustainable Energy Research (WISER), Illinois Institute of Technology, Chicago, IL 60616, United States 20 Gas hydrates; Hydration; Petroleum reservoir engineering, Flow modelling; Four-phase; Methane hydrates; Methane production; Model development; Phase flow; Phase model; Production test; Sand production; Solid deformation, Methane https://www.scopus.com/inward/record.uri?eid=2-s2.0-85130715390&doi=10.1021%2facs.iecr.2c00212&partnerID=40&md5=c2812197ef364669eb916f1af2c474ba cited By 0 D. Hinz H. Arastoopour J. Abbasian article Zhao2021 Class II hydrate deposits are characterized by a mobile water zone (WZ) underneath the hydrate-bearing layer (HBL) and are encountered in permafrost and deep-sea sediments. In this work, an efficient method of depressurization combining low-frequency electric heating under dual horizontal wells is proposed to exploit Class II hydrate deposits, in which two parallel horizontal wells are arranged in the HBL and the WZ. Based on the geological parameters in the Mallik deposit, the energy recovery behaviors are studied through a numerical simulation approach. Electric heating significantly improves hydrate dissociation and gas production compared with the depressurization method. However, gas production lags electric heating for a long time, and the energy efficiency ratio decreases with time in the later stage. To address these shortcomings, two additional electric heating schemes are designed and optimized. The results show that the additional wellbore heating at the beginning of production accelerates the dissociation of hydrates near the production well, thus greatly reducing the lag time. When electric heating is terminated after the 800th day, the cumulative gas production is reduced by 9.1%, but the energy efficiency ratio is improved as high as 48.71, which confirms the great potential of the proposed method. © 2021 Elsevier Ltd 2021 English 03605442 10.1016/j.energy.2021.121137 Energy 233 Elsevier Ltd Key Laboratory of Unconventional Oil & Gas Development (China University of Petroleum (East China)), Ministry of Education, Qingdao, 266580, China; Laboratory for Marine Mineral Resources, Qingdao National Laboratory for Marine Science and Technology, Qingdao, 266237, China; School of Petroleum Engineering, China University of Petroleum (East China), Qingdao, 266580, China Dissociation; Electric heating; Energy efficiency; Gas hydrates; Horizontal wells; Hydration, Class II; Depressurizations; Electrical heating; Energy; Energy recovery; Gas productions; Hydrate deposit; Lower frequencies; Thermal stimulation; Water zone, Deposits, energy efficiency; gas hydrate; gas production; numerical model; optimization; permafrost; simulation https://www.scopus.com/inward/record.uri?eid=2-s2.0-85107815547&doi=10.1016%2fj.energy.2021.121137&partnerID=40&md5=25afa891fa2354a57e36b0725678a722 cited By 11 E. Zhao J. Hou Y. Ji Y. Liu Y. Bai article Pan2020 Good knowledge of hydrate morphology and accurate quantification of hydrate saturation are significant for reservoir characterization, resource exploitation and geohazards assessment. Although many of empirical or theoretical models have been developed to detect hydrate morphology and predict hydrate saturation from elastic-wave velocities, they either fail to hold true for complex morphologies or cannot provide accurate hydrate saturation estimate. In this study, we propose a unified contact cementation theory by applying the modified Hashin-Shtrikman upper and lower bounds to an extended cementation theory. By merging the cementation theory and effective medium theory, it can be used to account for four types of hydrate morphologies. Numerical modeling results provide some new insights into effects of normalized thickness of hydrate layer, friction coefficient and effective pressure on elastic-wave velocities for different morphologies, which will be helpful for analyzing the borehole stability and determining optimum production-related strategies. In addition, we propose a hydrate morphology-based inversion method by introducing the ratio of multiple hydrate morphologies from statistical analyses and apply it to the acoustic logs from the Mallik 5L-38 permafrost-related gas hydrate research well in Mackenzie Delta and other three marine wells in Nankai Trough and Hikurangi margin. The velocity-based gas hydrate saturation estimations are in good agreement with those predicted from resistivity log and Nuclear Magnetic Resonance measurement, as well as core data, confirming feasibility and applicability of our theory and inversion method, and indicating its potential in seismic characterization of gas hydrate reservoirs. © 2019 Elsevier Ltd 2020 English 02648172 10.1016/j.marpetgeo.2019.104146 Marine and Petroleum Geology 113 Elsevier Ltd Research Institute of Petroleum Exploration and Development, Beijing, 100083, China; Department of Geosciences, University of Tulsa, Tulsa, OK 74104, United States; Beijing Research Institute of Uranium Geology, Beijing, 100029, China; Research Institute of China National Offshore Oil Corporation, Beijing, China; Research Institute of Petroleum Exploration and Development of Huabei Oil Field Company, Renqiu, Hebei 062552, China Acoustic logging; Acoustics; Boreholes; Cementing (shafts); Elastic waves; Electric logging; Friction; Gases; Hydration; Morphology; Nuclear magnetic logging; Velocity, Accurate quantifications; Effective medium theories; Elastic wave velocity; Gas hydrate saturations; Hikurangi margin; Hydrate saturation; Reservoir characterization; Unified contact cementation theory, Gas hydrates, detection method; elastic wave; estimation method; gas hydrate; hydrocarbon exploration; hydrocarbon reservoir; morphology; wave velocity https://www.scopus.com/inward/record.uri?eid=2-s2.0-85076162705&doi=10.1016%2fj.marpetgeo.2019.104146&partnerID=40&md5=4d0ce5f1ee11d2d92d7e47d33c91ab80 cited By 12 H. Pan H. Li J. Chen Y. Zhang S. Cai Y. Huang Y. Zheng Y. Zhao J. Deng article Xia2020 Natural gas hydrate is considered as one of the best potential alternative resource to address the world's energy demand. The available geological data at the Mallik site of Canada indicates the vertical heterogeneities of hydrate reservoir petrophysical properties. According to the logging data and sample analysis results at the Mallik 2L-38 well, a 2D model of geologically descriptive hydrate-bearing sediments was established to investigate the multiphase flow behaviors in hydrate reservoir induced by gas recovery and the effects of perforation interval on gas production performance. Firstly, the constructed model with vertical heterogeneous structures of permeability, porosity, and hydrate saturation was validated by matching the measured data in the Mallik 2007 test. The excessive residual methane in the hydrate reservoir observed in simulated results indicates insufficient gas production efficiency. For more effective methane recovery from a hydrate reservoir, the effect of perforation interval on long-term gas production performance was investigated based on the validated reservoir model. The simulation results suggest that both the location and length of the perforation interval have significant impact on hydrate dissociation behavior, while the gas production performance is mainly affected by the length of the perforation interval. To be specific, an excellent gas release performance is found in situations where the perforation interval is set at the interface between a hydrate reservoir and an underlying water-saturated zone. By increasing the perforation interval lengths of 5 m, 8 m, and 10 m, the gas release volumes from hydrate dissociation and gas production volumes from production wells are increased by 34%, 52%, and 57% and 37%, 58%, and 62%, respectively. © 2020 Yingli Xia et al. 2020 English 14688115 10.1155/2020/8833884 Geofluids 2020 Hindawi Limited Key Laboratory of Groundwater Resources and Environment, Ministry of Education, Jilin University, Changchun, 130021, China bearing capacity; gas hydrate; gas production; gas supply; hydrocarbon reservoir; natural gas; permeability; porosity; reservoir characterization; two-dimensional modeling, Canada https://www.scopus.com/inward/record.uri?eid=2-s2.0-85087566872&doi=10.1155%2f2020%2f8833884&partnerID=40&md5=67873319660d398b61a86e783c5e8562 cited By 6 Y. Xia T. Xu Y. Yuan X. Xin article Pan2020 Numerous models have been developed for prediction of gas hydrate saturation based on the microstructural relationship between gas hydrates and sediment grains. However, quantification of hydrate saturation and morphology from elastic properties has been hindered by failing to account for complex hydrate distributions. Here, we develop a generalized effective medium model by applying the modified Hashin-Shtrikman bounds to a newly developed cementation theory. This model is validated by experimental data for synthetic methane and tetrahydrofuran hydrates. Good comparison of model predictions with experimental measurements not only reveals its ability to merge the results of contact cementation theory and effective medium theory, but also indicates its feasibility for characterizing complex morphologies. Moreover, the results of inverting acoustic measurements quantitatively confirm that for synthetic samples in “excess-gas” condition gas hydrates mainly occur as a hybrid-cementing morphology with a low percentage of pore-filling morphology, whereas for pressure-core hydrate-bearing sediments in natural environments they exist as matrix-supporting and pore-filling morphologies with a very low percentage of hybrid-cementing morphology. The hydrate saturations estimated from sonic and density logs in several regions including northern Cascadia margin (Integrated Ocean Drilling Program Expedition 311, Hole U1326D and Hole U1327E), Alaska North Slope (Mount Elbert test well) and Mackenzie Delta (Mallik 5L-38), are comparable to the referenced hydrate saturations derived from core data and resistivity, and/or nuclear magnetic resonance log data, confirming validity and applicability of our model. Furthermore, our results indicate that ~8% hybrid-cementing, ~33% matrix-supporting and ~59% pore-filling hydrates may coexist in the fine-grained and clay-rich marine sediments on the northern Cascadia margin, whereas ~10% hybrid-cementing, ~54% matrix-supporting and ~36% pore-filling hydrates may coexist in the coarse-grained and sand-dominated terrestrial sediments of the Alaska North Slope and Mackenzie Delta. © 2019 The Authors 2020 English 02648172 10.1016/j.marpetgeo.2019.104166 Marine and Petroleum Geology 113 Elsevier Ltd Department of Geophysical Technology, Research Institute of Petroleum Exploration and Development, Beijing, 100083, China; Seismic Anisotropy Group, Department of Geosciences, The University of Tulsa, Tulsa, 74104, United States; GEOMAR, Helmhotz Center for Ocean Research, Kiel, Germany; Geotek Ltd., 4 Sopwith Way, Daventry, NN11 8PB, United Kingdom Cementing (shafts); Elastic waves; Filling; Gases; Hydration; Matrix algebra; Morphology; Nuclear magnetic logging; Radioactivity logging; Sediments; Software testing; Submarine geology, Effective medium model; Effective medium theories; Elastic wave velocity; Hydrate bearing sediments; Hydrate saturation; Integrated ocean drilling programs; Modified cementation theory; Nuclear magnetic resonance logs, Gas hydrates, cementation; elastic wave; gas hydrate; marine sediment; model validation; quantitative analysis; saturation; wave velocity, Alaska; Alaska Peninsula; Canada; Cascadia Margin; Mackenzie Delta; Northwest Territories; Pacific Ocean; United States https://www.scopus.com/inward/record.uri?eid=2-s2.0-85076492717&doi=10.1016%2fj.marpetgeo.2019.104166&partnerID=40&md5=89b94e6d2b49d822671142a58fb99081 cited By 10 H. Pan H. Li J. Chen M. Riedel M. Holland Y. Zhang S. Cai article Hinz2019 Numerous experimental studies have shown that hydrate dissociation can result in significant strength reduction leading to sediment failure and unconsolidated flow behavior. In this work, a constitutive model for the effective permeability is developed that is capable of accurately modeling the evolution of permeability in hydrate reservoirs exhibiting unconsolidated behavior. A production phase that promotes sand production from an unconsolidated hydrate reservoir will result in a significant increase in permeability, such that the reservoir essentially behaves like a naturally fracking reservoir. Furthermore, installation of a sand screen to prevent sand production will throttle gas production due to the significant decrease in permeability as solids accumulate and compact at the sand screen. Our model was developed and verified using experimental data from the Mallik 2007/2008 production tests and can be applied in simulations of the coupled hydrodynamics, heat transfer, mass transfer, and geomechanics in the unconsolidated hydrate reservoir. © 2019 Elsevier B.V. 2019 English 18755100 10.1016/j.jngse.2019.103033 Journal of Natural Gas Science and Engineering 72 Elsevier B.V. Department of Chemical and Biological Engineering, Wanger Institute for Sustainable Energy Research (WISER), Illinois Institute of Technology, Chicago, IL, United States Gas industry; Heat transfer; Hydrates; Hydration; Mass transfer; Sand, Effective permeability; Gas productions; Hydrate dissociation; Mallik; Production phase; Simulation; Strength reduction; Unconsolidated, Petroleum reservoir engineering https://www.scopus.com/inward/record.uri?eid=2-s2.0-85073981373&doi=10.1016%2fj.jngse.2019.103033&partnerID=40&md5=1053d477fb9fea30670aa03498a03101 cited By 11 D. Hinz H. Arastoopour J. Abbasian article Merey2019855 Gas hydrates are crystalline ice-like structures formed from water and gas molecules at high pressure and low temperature conditions. They are considered as near-future energy resources. Recently, there have been many drilling activities in gas hydrates in both permafrost regions (mainly Mallik wells, Canada; Ignik Sikumi #1 well, Alaska; Mount Elbert #1, Alaska) and marine sediments (the wells drilled in Gulf of Mexico and India drilling expeditions). In this study, it is aimed to evaluate and analyze logging-while drilling data (LWD) and other drilling data of these drilling activities. Initially, all drilling parameters (i.e. rate of penetration, weight on bit, torques, mud logs, etc.) of these wells were collected and drawn to see the change in parameters with depths. In order to indicate the changes in drilling parameters in the sediments containing gas hydrates, gas hydrate saturations were estimated from resistivity logs and NMR logs in this study. High resistivity log values and methane peaks in drilling fluid were good indicators of gas hydrate existence. During the drilling of permafrost formations and gas hydrates deposited in coarse sands as pore filling, the rate of penetration generally decreased. Differently, there was not almost any change in the rate of penetration during the drilling of fracture-filling gas hydrates within silts/clay in India. Borehole enlargements (washouts) were commonly seen in the wells drilled in marine sediments (Gulf of Mexico and Indian expeditions). However, this effect was minimum during the drilling of the wells in permafrost regions. This difference is due to the loose sediments in marine environment. Furthermore, gamma and density logs were seriously affected by washouts, mainly in marine sediments. It was observed that pore-filling gas hydrates affect the rate of penetration and keep the sediments stable because well collapses mainly occurred in the sediments without any gas hydrates. However, the temperature of drilling fluid should be close to the temperature of gas hydrate zones to reduce the effect of drilling on gas hydrate dissociation for the wells both in permafrost and marine sediments. In Gulf Mexico and Indian drilling expeditions, riser and wellhead equipment were not used. However, the usage of surface casing might decrease the risk of borehole collapses due to very loose sediments close to sea floor. Another important outcome of this study is that the pressure gradient follows hydrostatic pressure gradients according to the pressure analysis within gas hydrate stability zones of marine sediments. Finally, the analyses of drilling parameters revealed that drilling through gas hydrate bearing strata is not as risky as it might have been considered. The key is hidden in appropriate drilling design. © 2018 Elsevier B.V. 2019 English 09204105 10.1016/j.petrol.2018.08.079 Journal of Petroleum Science and Engineering 172 Elsevier B.V. 855-877 Batman University, Department of Petroleum and Natural Gas Engineering, Batman, Turkey Boring; Drilling; Drilling equipment; Drilling fluids; Electric logging; Filling; Gases; Hydration; Hydrostatic pressure; Infill drilling; Methane; Nuclear magnetic logging; Parameter estimation; Permafrost; Petroleum prospecting; Petroleum reservoir evaluation; Pressure gradient; Radioactivity logging; Renewable energy resources; Sediments; Submarine geology; Temperature; Well drilling, Borehole enlargements; Drilling of permafrost; Gas hydrate exploration wells; Gas hydrate saturations; Gas hydrate stability zones; Logging while drilling; Low temperature conditions; Methane hydrates, Gas hydrates, borehole; drilling; exploration; gas hydrate; gas well; marine sediment; methane; permafrost; pressure gradient, Atlantic Ocean; Gulf of Mexico; India https://www.scopus.com/inward/record.uri?eid=2-s2.0-85053061090&doi=10.1016%2fj.petrol.2018.08.079&partnerID=40&md5=4551dd54a7e624adfbe40984631f1f49 cited By 25 Ş. Merey article Yang20192133 Natural gas hydrate (NGH) has been widely considered as an alternative form of energy with huge potential, due to its tremendous reserves, cleanness and high energy density. Several countries involving Japan, Canada, India and China have launched national projects on the exploration and exploitation of gas hydrate resources. At the beginning of this century, an early trial production of hydrate resources was carried out in Mallik permafrost region, Canada. Japan has conducted the first field test from marine hydrates in 2013, followed by another trial in 2017. China also made its first trial production from marine hydrate sediments in 2017. Yet the low production efficiency, ice/hydrate regeneration, and sand problems are still commonly encountered; the worldwide progress is far before commercialization. Up to now, many gas production techniques have been proposed, and a few of them have been adopted in the field production tests. Nevertheless, hardly any method appears really promising; each of them shows limitations at certain conditions. Therefore, further efforts should be made on the economic efficiency as well as sustainability and environmental impacts. In this paper, the investigations on NGH exploitation techniques are comprehensively reviewed, involving depressurization, thermal stimulation, chemical inhibitor injection, CO2–CH4 exchange, their combinations, and some novel techniques. The behavior of each method and its further potential in the field test are discussed. The advantages and limitations of laboratory studies are also analyzed. The work could give some guidance in the future formulation of exploitation scheme and evaluation of gas production behavior from hydrate reservoirs. © 2019 Elsevier B.V. 2019 English 10049541 10.1016/j.cjche.2019.02.028 Chinese Journal of Chemical Engineering 27 Materials China 2133-2147 Key Laboratory of Ocean Energy Utilization and Energy Conservation of Ministry of Education, Dalian University of Technology, Dalian, 116024, China; Guangzhou Marine Geological Survey, Guangzhou, 510075, China; China Ship Design & Research Center Co., Ltd., Dalian, 116001, China 9 Carbon dioxide; Environmental impact; Gas industry; Gases; Hydration; Ice problems; Natural gas; Petroleum reservoir evaluation; Production; Proven reserves; Sustainable development, CO2 exchange; Depressurizations; Exploitation techniques; Exploration and exploitation; Gas production technique; Production efficiency; Production techniques; Thermal stimulation, Gas hydrates https://www.scopus.com/inward/record.uri?eid=2-s2.0-85066497415&doi=10.1016%2fj.cjche.2019.02.028&partnerID=40&md5=be9bb9d34c1d06ec19913f2e37dc3db7 cited By 72 L. Yang Y. Liu H. Zhang B. Xiao X. Guo R. Wei L. Xu L. Sun B. Yu S. Leng Y. Li article Mohammadmoradi2018786 The identification of methane hydrate behavior in porous media is one of the most challenging yet rewarding pore-level visualization and simulation tasks. The hydrate morphology influences the physical characteristics of the host sediments as during the hydrate formation and dissociation processes the pore space and flow pathways constantly evolve. Here, a direct three-phase pore morphological simulation approach is proposed, verified and utilized to simulate hydrate deformities and predict fluid occupancies and absolute and effective permeabilities of hydrate-bearing geological formations. The proposed technique simulates capillary-dominant displacements by applying a set of geomaterial rules directly to the pixels of pore-level porous media images. The case studies are sandy microstructures generated based on the particle size distributions of the Mallik gas hydrate deposit. The fluid occupancy profiles, absolute permeability, and hydraulic tortuosity curves are comparable with the experimental datasets. The sensitivity analysis shows that although the gas relative permeability is less sensitive to the hydrate specifications, the porosity, grain size distribution, and hydrate content and occupancy remarkably influence the rock absolute permeability. © 2017 Elsevier Ltd 2018 English 02648172 10.1016/j.marpetgeo.2017.11.016 Marine and Petroleum Geology 89 Elsevier Ltd 786-798 University of Calgary, Canada Dissociation; Gas permeability; Grain size and shape; Hydration; Methane; Particle size; Porous materials; Sensitivity analysis; Size distribution, Absolute permeability; Effective permeability; Gas relative permeabilities; Geometrical simulations; Grain size distribution; Morphological simulation; Physical characteristics; Visualization and simulation, Gas hydrates, displacement; hydrocarbon reservoir; methane; microstructure; permeability; pore space; porous medium; sensitivity analysis https://www.scopus.com/inward/record.uri?eid=2-s2.0-85033802254&doi=10.1016%2fj.marpetgeo.2017.11.016&partnerID=40&md5=60119c252c34c2bd2ac90435e8731ebd cited By 20 P. Mohammadmoradi A. Kantzas article Konno2018662 The authors would like to replace the section 1. 1ntroduction (pp. 425) with the following: Introduction Methane hydrate, which is a crystalline compound formed from methane and water, is found in arctic and marine continental margin sediments worldwide (Sloan and Koh, 2008). The P-wave velocity of hydrate-bearing sediments is higher than that of hydrate-free unconsolidated sediments (e.g., Yuan et al., 1996), and laboratory experiments have shown that there is a strong relationship between the P-wave velocity and hydrate saturation (e.g., Berge et al., 1999). Through the comparison with model predictions such as those of Dvorkin et al. (2000), it was found that this relationship depends on the hydrate morphology, such as grain coating, cementing, pore-filling, and sediment frame component (or load-bearing) within the pore space (M. Lee et al., 1996; Berge et al., 1999; Reister, 2003; Yun et al., 2005; Priest et al., 2009; J. Lee et al., 2010; Hu et al., 2010, Li et al., 2011; Best et al., 2013; Kim et al., 2013a). This suggests that the P-wave velocity obtained from logging and seismic surveys can be used to estimate the in situ hydrate saturation if the hydrate morphology in actual reservoirs is revealed. P-wave velocity changes during CH4eCO2 replacement in hydrates have also been studied to estimate the sediment stiffness (Espinoza and Santamarina, 2011; Liu et al., 2013). It is therefore important to understand the relationship between the P-wave velocity, hydrate saturation, and hydrate morphology because these properties are deeply linked to the physical properties of hydrate-bearing sediments, such as their permeability, thermal properties, electrical conductivity, and shear strength (Waite et al., 2009; Santamarina and Ruppel, 2010). Quantitative detection of methane hydrate in natural sediments has been attempted over the years. Wood et al. (1994) analyzed seismic interval velocities at the Blake Ridge for quantitative detection of methane hydrate. Chand et al. (2004) compared P- wave velocities predicted by four models and field data from the Mallik field in the Mackenzie Delta and the Blake Ridge. At the Mallik field, Carcione and Gei (2004) estimated hydrate saturation from well logging data and vertical seismic profiles by assuming that the hydrate filled pore space (pore-filling). Dash and Spence (2011) estimated hydrate saturation at the northern Cascadia margin using P-wave and S-wave velocities. They concluded that the hydrate is distributed as part of the load-bearing matrix. For other areas, such as the Nankai Trough, Mount Elbert, the KrishnaeGodavari basin, the Tsushima Basin, and the Shenhu area of the South China Sea, estimations of hydrate saturation have also been conducted (Inamori et al., 2010; Lee and Collett, 2011; Kim et al., 2013b; Shankar and Riedel, 2011; Lee and Collett, 2013; Wang et al., 2014). Hydrate morphology was estimated as load-bearing at the Nankai Trough, Mount Elbert, and the KrishnaeGodavari basin, whereas it was estimated to be pore-filling at the Tsushima Basin. Winters et al. (2004) reported that the mildly-disturbed samples recovered from the 2L-38 well at the Mallik field are best modeled as part of the sediment frame (load-bearing). Laboratory experiments using artificial cores have also provided insight into the relationship between P-wave velocity and hydrate saturation; however, there are some limitations to the use of artificial cores in estimating hydrate saturation in natural sediments. One of the reasons is that it is difficult to control hydrate morphology in such a way as to mimic natural features in artificial cores. Hydrate formed in a gas-rich environment, which is a conventional method used in laboratory studies, generally shows a cementing morphology (Winters et al., 2004; Priest et al., 2005, 2006). In contrast, hydrate formed from methane dissolved in the pore fluid, which is considered as common in natural environments, may not show a cementing morphology (Spangenberg et al., 2005, 2008; Winters et al., 2007). Using a non-methane hydrate former, Yun et al. (2005) and Lee et al. (2010) documented a transition between pore-filling and load-bearing hydrates at saturation of ~40%e50% of pore space. Gas hydrate morphology in natural sediments is depends on the hydrate occurrence mechanism; however, it is difficult to know the occurrence mechanism for each reservoir. Analysis of logging data seems to be effective in estimating the actual relationship between P-wave velocity, hydrate saturation, and hydrate morphology in natural sediments. However, the spatial resolution of P-wave velocity data and hydrate saturation data, as estimated from resistivity logging, is larger than that of core data, and the various datasets are not usually entirely coincident. Thus, cross-plots of P- wave velocity and hydrate saturation are often so scattered that it is difficult to accurately constrain the hydrate morphology. In addition, the frequency used for in situ exploration is much lower than that used in laboratory experiments, which results in differences in the depth and spatial resolution of measurements. In situ exploration data are spatially-averaged and appropriate for the determination of the hydrate distribution in bulk sediments. However, such data are difficult to apply to the investigation of local properties, such as the pore space hydrate morphology. Consequently, high frequency laboratory experiments using natural sediments are more favorable for the analysis of pore space hydrate morphology. Pressure core analysis technologies now enable the study of relatively undisturbed samples recovered from hydrate-bearing natural sediments, and pressure core analyses of P-wave veloc ities have been conducted for hydrate-bearing natural sediments (Yun et al., 2006, 2010, 2011; Schultheiss et al., 2011). Lee et al. (2013) successfully determined the relationship between P-wave velocity and hydrate saturation from pressure cores recovered from the Tsuhima Basin. They concluded that the hydrate morphology is pore-filling at low hydrate saturations, but gradually deviates from pore-filling toward cementation as hydrate saturation increases, in accordance with studies of Yun et al. (2005) and Lee et al. (2010). They used the Pressure Core Analysis and Transfer System (PCATS) developed by Geotek Ltd. (Schultheiss et al., 2011) to measure P- wave velocity through the core liner at high resolution. However, the study noted that the data resolving hydrate saturation was much lower than that of P-wave velocity because hydrate saturation was calculated based on a dissociation experiment conducted on the whole core including both high and low P-wave velocity sections (Lee et al., 2013). In this study, a newly developed pressure core cutting, manipulating, and analyzing system was used to overcome the discrepancy of data resolution between P-wave velocity and hydrate saturation. P-wave velocity was measured by the PCATS at a high resolution using pressure cores recovered from the Eastern Nankai Trough offshore Japan. After the P-wave velocity measurements, the cores were cut into pieces under pressure for separate P-wave velocity intervals on the basis of visual observation enabled by our pressure core system. To obtain high resolution hydrate-saturation data, each sub-sampled core was depressurized and the gas volume was measured. By comparing experimental data with physical model predictions, hydrate morphology in pore space was studied in detail. The authors would like to apologise for any inconvenience caused. DOI of original article: dx.doi.org/10.1016/j.marpetgeo.2015.02.021 © 2018 2018 English 02648172 10.1016/j.marpetgeo.2018.02.022 Marine and Petroleum Geology 91 Elsevier Ltd 662-663 Methane Hydrate Research Center (MHRC), National Institute of Advanced Industrial Science and Technology (AIST), 2-17-2-1 Tsukisamu-Higashi, Toyohira-Ku, Sapporo, 062-8517, Japan; MHRC, AIST, 16-1 Onogawa, Tsukuba, Ibaraki, 305-8569, Japan; Methane Hydrate Research & Development Division, Japan Oil, Gas and Metals National Corporation (JOGMEC), 1-2-2 Hamada, Mihama-ku, Chiba-city, Chiba, 261-0025, Japan https://www.scopus.com/inward/record.uri?eid=2-s2.0-85045074980&doi=10.1016%2fj.marpetgeo.2018.02.022&partnerID=40&md5=691c5d7cc663fa7dc3297ebbbabaf816 cited By 0 Y. Konno Y. Jin J. Yoneda M. Kida K. Egawa T. Ito K. Suzuki J. Nagao article Terry2018MR317 A unified effective medium model is developed to incorporate the endpoints of perfectly smooth and infinitely rough sphere components and to allow partitioning between rough and smooth grains. We incorporate the unified model into the framework for gas hydrates in unconsolidated sediments using pore-fluid and rock-matrix configurations for grain placement, while reviewing other developments that have taken place in the past four decades. The unified rock-matrix model is validated with data available from the 2002 Mallik gas hydrates project well 5L-38. Gas-hydrate saturation and neutron-porosity logs from this well are used to generate synthetic P- and S-wave velocity models for several values of the friction coefficient. First, we overlaid crossplots of P- versus S-wave velocities for synthetic and measured velocities, and we compared the match until a good choice was found for the friction coefficient. Second, we plotted the synthetic velocities as separate logs of P- and S-wave velocities for each friction coefficient; the synthetic velocity logs were then overlaid on the measured velocities calculated from the sonic logs. Results of a direct comparison of the synthetic and measured velocity logs provide valuable insights into the validation of the unified effective medium model. Recognizing the significance of the Hertz-Mindlin-type effective medium models for gas hydrates in unconsolidated sediments, we incorporate the previous efforts into a single "unified" model and define a common nomenclature. Although we attempt to assign a single friction coefficient value to each hydrate window, it is not surprising that in a real and heterogeneous environment, the value might vary with depth, as it does here at the larger spatial scales. We determine and quantitatively estimate that gas hydrates in sediments are well-predicted with a friction coefficient closer to a smooth sphere model than a rough sphere model. © 2018 Society of Exploration Geophysicists. All rights reserved. 2018 English 00168033 10.1190/geo2017-0513.1 Geophysics 83 Society of Exploration Geophysicists MR317-MR332 University of South Carolina, School of the Earth, Ocean, and Environment, Columbia, SC 29208, United States 6 Algorithms; Elastic moduli; Friction; Gases; Hydration; Models; Neutron logging; Sediments; Shear waves; Spheres; Velocity; Wave propagation, Effective medium model; Friction coefficients; Gas hydrate saturations; Heterogeneous environments; Neutron porosity logs; P- and S-wave velocities; Rock physics; Unconsolidated sediment, Gas hydrates, algorithm; bulk modulus; gas hydrate; numerical model; P-wave; S-wave; sediment analysis; shear modulus; surface roughness; wave velocity https://www.scopus.com/inward/record.uri?eid=2-s2.0-85054152907&doi=10.1190%2fgeo2017-0513.1&partnerID=40&md5=aabfa7db7c0080e4f98806277f8a25f3 cited By 8 D.A. Terry C.C. Knapp article Cook20182069 Accurately quantifying the amount of naturally occurring gas hydrate in marine and permafrost environments is important for assessing its resource potential and understanding the role of gas hydrate in the global carbon cycle. Electrical resistivity well logs are often used to calculate gas hydrate saturations, Sh, using Archie's equation. Archie's equation, in turn, relies on an empirical saturation parameter, n. Though n = 1.9 has been measured for ice-bearing sands and is widely used within the hydrate community, it is highly questionable if this n value is appropriate for hydrate-bearing sands. In this work, we calibrate n for hydrate-bearing sands from the Canadian permafrost gas hydrate research well, Mallik 5L-38, by establishing an independent downhole Sh profile based on compressional-wave velocity log data. Using the independently determined Sh profile and colocated electrical resistivity and bulk density logs, Archie's saturation equation is solved for n, and uncertainty is tracked throughout the iterative process. In addition to the Mallik 5L-38 well, we also apply this method to two marine, coarse-grained reservoirs from the northern Gulf of Mexico Gas Hydrate Joint Industry Project: Walker Ridge 313-H and Green Canyon 955-H. All locations yield similar results, each suggesting n ≈ 2.5 ± 0.5. Thus, for the coarse-grained hydrate bearing (Sh &gt; 0.4) of greatest interest as potential energy resources, we suggest that n = 2.5 ± 0.5 should be applied in Archie's equation for either marine or permafrost gas hydrate settings if independent estimates of n are not available. ©2018. American Geophysical Union. All Rights Reserved. 2018 English 21699313 10.1002/2017JB015138 Journal of Geophysical Research: Solid Earth 123 Blackwell Publishing Ltd 2069-2089 School of Earth Science, The Ohio State University, Columbus, OH, United States; U.S. Geological Survey, Woods Hole, MA, United States 3 carbon cycle; electrical resistivity; gas hydrate; hydrocarbon reservoir; marine environment; natural gas; permafrost; saturation; wave velocity, Atlantic Ocean; Gulf of Mexico https://www.scopus.com/inward/record.uri?eid=2-s2.0-85045830707&doi=10.1002%2f2017JB015138&partnerID=40&md5=ce4a46746d7b239ee480f056a990fea9 cited By 76 A.E. Cook W.F. Waite article He2017368 Marine gas hydrate is an important resource of clean energy for the future, but its exploitation requires not only the innovation of development techniques but also serious consideration of protection of marine environment. For a timely response to production process, monitoring of the dynamic change of gas hydrate reservoir in real time is a basic requirement for a successful exploitation. However, in previous successful gas hydrate production experiments, either in terrestrial permafrost area (Mallik of Canada and Ignik Sikumi of USA) or on continental slope in deep sea (Nankai Trough of Japan), monitoring was carried out mainly through the instruments installed in the two or three observation wells which were only tens of meters away from the production well, and consequently the monitoring might have covered only a limited area. At the present the monitoring technique for large-scale monitoring of gas hydrate reservoir has not been established worldwide, even systematic discussion and scheme design are absent. Based on the acoustic and electrical responses to the saturation change and granular contact mode of gas hydrate layer, several seismic and electromagnetic exploration methods have been compared to see their feasibility and merits and drawbacks for large-scale monitoring of marine gas hydrate development, and an advanced geophysical monitoring scheme is proposed for the upcoming gas hydrate experimental production in South China Sea and future commercial exploitation. The integrated geophysical monitoring system is comprised of (1) a set of geophysical sensors to be installed in the observation wells, which will continuously collect the key physical parameters as temperature, pressure, electrical resistivity, streaming potential, heat flux, etc.; (2) a high sensitive and endurable full fiber 4-component ocean bottom seismic cable system to record the time lapse variations of reservoir acoustic properties of both compressive and shear waves; (3) a net of multifunctional ocean bottom nodes around the production well to measure the seafloor surface deformation/depression during production, and to directly detect and visually observe possible methane leakage. On a well designed protocol, this monitoring system can quantitatively measure the key geophysical variations associated with gas hydrate dissociation, and the data to be acquired will provide scientific basis for production optimization, environment protection and risk assessment for marine gas hydrate exploitation. © 2017, Editorial Office of Earth Science Frontiers. All right reserved. 2017 Chinese 10052321 10.13745/j.esf.yx.2016-11-27 Earth Science Frontiers 24 Science Frontiers editorial department 368-382 School of Earth and Space Sciences, Peking University, Key Laboratory of Orogenic Belts and Crustal Evolution, Beijing, 100871, China; Department of Energy & Resources Engineering, College of Engineering, Peking University, Beijing, 100871, China; Institute of Ocean Research, Peking University, Beijing, 100871, China; Guangzhou Marine Geological Survey, China Geological Survey, Guangzhou, 510760, China 5 Acoustic properties; Deformation; Earthquake effects; Electromagnetic prospecting; Gas hydrates; Gases; Geophysics; Heat flux; Hydration; Risk assessment; Seismology; Shear flow; Shear waves, Commercial exploitation; Gas-hydrate production; Geophysical monitoring; MCSEM; Production optimization; Reservoir monitoring; Seafloor deformation; Seismic system, Monitoring https://www.scopus.com/inward/record.uri?eid=2-s2.0-85029622267&doi=10.13745%2fj.esf.yx.2016-11-27&partnerID=40&md5=9a932a1d6253eadc0c7f868359c75165 cited By 13 T. He H. Lu J. Lin Y. Dong J. He article Rezaee20171727 A new approach is described to allow conditioning to both hard data (HD) and soft data for a patch- and distance-based multiple-point geostatistical simulation. The multinomial logistic regression is used to quantify the link between HD and soft data. The soft data is converted by the logistic regression classifier into as many probability fields as there are categories. The local category proportions are used and compared to the average category probabilities within the patch. The conditioning to HD is obtained using alternative training images and by imposing large relative weights to HD. The conditioning to soft data is obtained by measuring the probability–proportion patch distance. Both 2D and 3D cases are considered. Synthetic cases show that a stationary TI can generate non-stationary realizations reproducing the HD, keeping the texture indicated by the TI and following the trends identified in probability maps obtained from soft data. A real case study, the Mallik methane-hydrate field, shows perfect reproduction of HD while keeping a good reproduction of the TI texture and probability trends. © 2016, Springer-Verlag Berlin Heidelberg. 2017 English 14363240 10.1007/s00477-016-1277-8 Stochastic Environmental Research and Risk Assessment 31 Springer New York LLC 1727-1745 Department of Civil, Geological and Mining, Polytechnique Montréal, C.P. 6079 Succ. Centre-ville, Montreal, QC H3C 3A7, Canada 7 Facsimile; Gas hydrates; Hydration; Regression analysis, Distance functions; Geostatistical simulation; Logistic regression classifier; Methane hydrates; Multinomial logistic regression; Multiple-point geostatistics; Patch based; Soft data, Probability, computer simulation; data set; gas hydrate; geostatistics; methane; probability; regression analysis https://www.scopus.com/inward/record.uri?eid=2-s2.0-84976321931&doi=10.1007%2fs00477-016-1277-8&partnerID=40&md5=6b4589372bfa12ddb1ca0b6772ff6d8f cited By 9 H. Rezaee D. Marcotte article Sun20161016 Seismic attenuation and velocity dispersion are potentially able to reveal the rock physical properties of the subsurface. Conventionally, a frequency-independent quality factor (Q) is measured. This Q is equivalent to the total velocity dispersion in a seismic record and is inadequate for analysing the attenuation mechanism or rock physical properties. Here a new method is proposed to extract the velocity dispersion curves so that more attributes can be obtained from full-waveform multichannel sonic logging data, especially the critical frequency (fc) if it is within the bandwidth of the data. This method first decomposes the seismic data into a series of frequency components, computes the semblance of each frequency component for different velocity values, cross-correlates the semblance matrices of adjacent frequency components to get the velocity gradients, and finally integrates to obtain a velocity dispersion curve. Results of this method are of satisfactory accuracy and robustness. This method is applied to the data acquired in Mallik 5L-38 gas hydrate research well in Mackenzie Delta, Northwest Territories, Canada. The observed P-wave velocity dispersion compares well with the geological setting. In the gas hydrate zone (about 900 m–1100 m), high concentration of gas hydrate causes very strong velocity dispersion and a distinct fc at about 15 kHz, likely due to strong scattering of centimetre-scale inclusions of gas hydrate; concurrently, water flow in connected cracks in some ranges of this zone adds a large part of velocity dispersion and a dimmer fc at about 9.5 kHz. Immediate underneath the gas hydrate zone, abundant free water in weakly laminated sediments causes quite strong velocity dispersion and an fc at about 6.5 kHz. Velocity dispersion is mild and without an obvious fc in sediments above the gas hydrate zone. © 2016 European Association of Geoscientists & Engineers 2016 English 00168025 10.1111/1365-2478.12410 Geophysical Prospecting 64 Blackwell Publishing Ltd 1016-1029 State Key Laboratory of Petroleum Resources and Prospecting, China University of Petroleum-Beijing, Beijing, 102249, China; Department of Earth Sciences, University of Toronto, Toronto, ON M5S 3B1, Canada; Department of Geological Sciences, University of Texas at Austin, Austin, TX 78712, United States 4 Acoustic logging; Flow of water; Gas hydrates; Gases; Hydration; Physical properties; Seismic waves; Seismology; Velocity; Wave propagation, Critical frequencies; Frequency components; Frequency independent; Geological setting; Laminated sediments; Rock physical properties; Seismic attenuation; Velocity dispersion, Dispersion (waves), data acquisition; gas hydrate; logging (geophysics); P-wave; Q factor; rock property; seismic attenuation; seismic velocity; wave dispersion; waveform analysis, Canada; Mackenzie Delta; Northwest Territories https://www.scopus.com/inward/record.uri?eid=2-s2.0-84977559993&doi=10.1111%2f1365-2478.12410&partnerID=40&md5=be1720ff72057437823d0632c479edf8 cited By 4 L.F. Sun B. Milkereit N. Tisato article Heeschen20166210 Gas hydrate production is still in the test phase. It is only now that numerical models are being developed to describe data and production scenarios. Laboratory experiments are carried out to test the rationale of the conceptual models and deliver input data. Major experimental challenges include (I) the simulation of a natural three-phase system of sand-hydrate-liquid with known and high hydrate saturations and (II) the simulation of transport behavior as deduced from field data. The large-scale reservoir simulator (LARS; 210 L sample) at the GFZ has met these challenges and allowed for the first simulation of the gas production test from permafrost hydrates at the Mallik drill site (Canada) via multistage depressurization. At the starting position, hydrate saturation was as high as 90%, formed from dissolved methane only. Whereas gas hydrate dissociation determined the flow patterns in the early pressure stages, the importance of different transport behaviors increased at lower pressure stages and increasing water content. Gas flow patterns as observed in Mallik were recorded. While the conceptual model for the experimental data does agree with the model proposed for Mallik at moderate and low gas production, it is different at high gas production rates. © 2016 American Chemical Society. 2016 English 08870624 10.1021/acs.energyfuels.6b00297 Energy and Fuels 30 American Chemical Society 6210-6219 GFZ German Research Centre for Geosciences, Telegrafenberg, Potsdam, 14473, Germany 8 Flow of gases; Flow patterns; Gases; Hydration; Methane, Gas production test; Gas-hydrate production; Hydrate dissociation; Laboratory experiments; Laboratory simulation; Reservoir simulator; Three phase system; Transport behavior, Gas hydrates https://www.scopus.com/inward/record.uri?eid=2-s2.0-84983670449&doi=10.1021%2facs.energyfuels.6b00297&partnerID=40&md5=a224d8f5a496b788fbbdbb44e22935d2 cited By 73 K.U. Heeschen S. Abendroth M. Priegnitz E. Spangenberg J. Thaler J.M. Schicks article Mahabadi20163099 The water retention curve and relative permeability are critical to predict gas and water production from hydrate-bearing sediments. However, values for key parameters that characterize gas and water flows during hydrate dissociation have not been identified due to experimental challenges. This study utilizes the combined techniques of micro-focus X-ray computed tomography (CT) and pore-network model simulation to identify proper values for those key parameters, such as gas entry pressure, residual water saturation, and curve fitting values. Hydrates with various saturation and morphology are realized in the pore-network that was extracted from micron-resolution CT images of sediments recovered from the hydrate deposit at the Mallik site, and then the processes of gas invasion, hydrate dissociation, gas expansion, and gas and water permeability are simulated. Results show that greater hydrate saturation in sediments lead to higher gas entry pressure, higher residual water saturation, and steeper water retention curve. An increase in hydrate saturation decreases gas permeability but has marginal effects on water permeability in sediments with uniformly distributed hydrate. Hydrate morphology has more significant impacts than hydrate saturation on relative permeability. Sediments with heterogeneously distributed hydrate tend to result in lower residual water saturation and higher gas and water permeability. In this sense, the Brooks-Corey model that uses two fitting parameters individually for gas and water permeability properly capture the effect of hydrate saturation and morphology on gas and water flows in hydrate-bearing sediments. © 2016. American Geophysical Union. All Rights Reserved. 2016 English 15252027 10.1002/2016GC006372 Geochemistry, Geophysics, Geosystems 17 Blackwell Publishing Ltd 3099-3110 School of Sustainable Engineering and the Built Environment, Arizona State University, Tempe, AZ, United States; School of Civil and Environmental Engineering, Georgia Institute of Technology, Atlanta, GA, United States; National Energy Technology Laboratory, Morgantown, WV, United States; Department of Civil and Environmental Engineering, Yonsei University, Seoul, South Korea 8 Computerized tomography; Curve fitting; Dissociation; Flow of water; Gas permeability; Gases; Hydration; Hydraulics; Morphology; Sediments, Brooks-Corey model; Hydrate bearing sediments; Pore-network modeling; Relative permeability; Van Genuchten model; Water retention curve, Gas hydrates, gas hydrate; gas production; hydrocarbon reservoir; numerical model; permeability; porosity; water retention https://www.scopus.com/inward/record.uri?eid=2-s2.0-84982803665&doi=10.1002%2f2016GC006372&partnerID=40&md5=c33fb617e8266ead9dd1030b8bbee488 cited By 114 N. Mahabadi S. Dai Y. Seol T. Sup Yun J. Jang article Riedel2014292 Shear wave velocity data have been acquired at several marine gas hydrate drilling expeditions, including the India National Gas Hydrate Program Expedition 1 (NGHP-01), the Ocean Drilling Program (ODP) Leg 204, and Integrated Ocean Drilling Program (IODP) Expedition 311 (X311). In this study we use data from these marine drilling expeditions to develop an understanding of general grain-size control on the P- and S-wave properties of sediments. A clear difference in the downhole trends of P-wave (Vp) and S-wave (Vs) velocity and the Vp/Vs ratio from all three marine regions was observed: the northern Cascadia margin (IODP X311) shows the highest P-wave and S-wave velocity values overall and those from the India margin (Expedition NGHP-01) are the lowest. The southern Cascadia margin (ODP Leg 204) appears to have similar low P-wave and S-wave velocity values as seen off India. S-wave velocity values increase relative to the sites off India, but they are not as high as those seen on the northern Cascadia margin. Such regional differences can be explained by the amount of silt/sand (or lack thereof) occurring at these sites, with northern Cascadia being the region of the highest silt/sand occurrences. This grain-size control on P-wave and S-wave velocity and associated mineral composition differences is amplified when compared to the Arctic permafrost environments, where gas hydrate predominantly occurs in sand- and silt-dominated formations. Using a cross-plot of gamma ray values versus the Vp/Vs ratio, we compare the marine gas hydrate occurrences in these regions: offshore eastern India margin, offshore Cascadia margin, the Ignik-Sikumi site in Alaska, and the Mallik 5L-38 site in the Mackenzie Delta. The log-data from the Arctic permafrost regions show a strongly linear Vp-Vs relationship, similar to the previously defined empirical relationships by Greenberg and Castagna (1992). P- and S-wave velocity data from the India margin and ODP Leg 204 deviate strongly from these linear trends, whereas data from IODP X311 plot closer to the trend of the Arctic data sets and previously published relationships. Three new linear relationships for different grain size marine sediment hosts are suggested:. a)mud-dominated (Mahanadi Basin, ODP Leg 204 & NGHP-01-17): Vs=1.5854×Vp-2.1649b)silty-mud (KG Basin): Vs=0.8105×Vp-1.0223c)silty-sand (IODP X311): Vs=0.5316×Vp-0.4916We investigate the relationship of gas hydrate saturation determined from electrical resistivity on the Vp/Vs ratio and found that the sand-dominated Arctic hosts show a clearly decreasing trend of Vp/Vs ratio with gas hydrate saturation. Though limited due to lower overall GH saturations, a similar trend is seen for sites from IODP X311 and at the ash-dominated NGHP-01-17 sediment in the Andaman Sea. Gas hydrate that occurs predominantly in fractured clay hosts show a different trend where the Vp/Vs ratio is much higher than at sand-dominated sites and remains constant or increases slightly with increasing gas hydrate saturation. This trend may be the result of anisotropy in fracture-dominated systems, where P- and S-wave velocities appear higher and Archie-based saturations of gas hydrate are overestimated. Gas hydrate concentrations were also estimated in these three marine settings and at Arctic sites using an effective medium model, combining P- and S-wave velocities as equally weighted constraints on the calculation. The effective medium approach generally overestimates S-wave velocity in high-porosity, clay-dominated sediments, but can be accurately used in sand-rich formations. © 2014. 2014 English 02648172 10.1016/j.marpetgeo.2014.07.028 Marine and Petroleum Geology 58 Elsevier Ltd 292-320 Natural Resources Canada, Geological Survey of Canada - Pacific, 9860 West Saanich Road, Sidney, BC V8L4B2, Canada; Borehole Research Group, Lamont-Doherty Earth Observatory of Columbia University, Palisades, NY 10964, United States PA https://www.scopus.com/inward/record.uri?eid=2-s2.0-85027932674&doi=10.1016%2fj.marpetgeo.2014.07.028&partnerID=40&md5=bdd7df78039250edde67c9a5879e144f cited By 20 M. Riedel D. Goldberg G. Guerin article Uddin201440 The Mallik gas hydrate deposit was found to consist of 3 distinct, highly concentrated, high quality zones of structure I hydrate with partial occupancy of 5.75-6.2. Earlier simulation studies focused on history matching the 6 days production test of the lower zone, assuming 100% hydrate occupancy. The focus of the current study is on a simulation comparison of the expected response of the three hydrate bearing zones (lower, middle and upper) of the Mallik well 2L-38 to a single vertical well depressurization test. Additionally, a revised history match of the bottom zone field test considering partial gas occupancy of the hydrate, and a further assessment of the kinetic dissociation model are studied. This study extends the previously developed model found to successfully represent the physical and thermodynamic mechanisms involved with hydrate dissociation in the Mallik field test.The simulation results indicate that hydrate production from the middle hydrate zone is feasible and attractive, while production from the upper zone is not, due to its low pressure/temperature condition. Generally speaking, all three zones showed a similar role of the bottom aquifer in determining the water and gas flows, and all three zones showed an upward gas migration block by different existing hydrate layers. This effect is contrary to gas production from conventional gas reservoirs and indicates that the use of horizontal wells in such reservoirs may not be attractive.This study has also explored the role of partial gas cavity occupancy in the lower zone production characteristics and a re-history match of the 6 days Mallik production test showed an improved match and some indication about partial occupancy close to 6.88. Finally an in-depth examination of a previously reported laboratory scale study of methane hydrate decomposition and some observations from even smaller scale molecular dynamics study gave exciting clues of how to further interpret and improve our kinetic gas hydrate model, to be used at multiple time and length scales. Such an improved model has been proposed and awaits further testing and matching of appropriate data. © 2014. 2014 English 18755100 10.1016/j.jngse.2014.07.027 Journal of Natural Gas Science and Engineering 21 Elsevier B.V. 40-63 Alberta Innovates - Technology Futures, Edmonton, AB T6N 1E4, Canada; Geological Survey of Canada, Natural Resources Canada, Sidney, BC V8L 4B2, Canada; Computer Modeling Group Ltd., Calgary, AB T2L 2A6, Canada Aquifers; Dissociation; Gas industry; Gases; Horizontal wells; Hydration; Molecular dynamics; Petroleum reservoirs, Depressurizations; Hydrate dissociation; Hydration number; Salinity; Simulation, Gas hydrates https://www.scopus.com/inward/record.uri?eid=2-s2.0-84906061751&doi=10.1016%2fj.jngse.2014.07.027&partnerID=40&md5=b1a7585369cda69488c84bc6152e3423 cited By 52 M. Uddin F. Wright S. Dallimore D. Coombe article Uddin2014250 The delineation of the Mallik gas hydrate field has utilized extensive well logging and substantial 3D seismic testing and interpretation. This study explores the use of seismic data to quantify the areally heterogeneous gas hydrate distribution. The available Mallik 3D seismic data was compiled and compared/contrasted with available well log data from two adjacent wells. Based on the seismic information, two areally variable (i.e. non-homogeneous) scenarios for gas hydrate distributions are considered: Scenario I having the same initial total hydrate amount as our earlier model areally uniform (homogeneous) distribution, and Scenario II with significantly less overall total hydrate, but honouring the same relative distribution. The scenarios of variable gas hydrate distributions are used in dynamic simulations of the lower Mallik zone. Simulations of each were conducted with and without the role of geomechanics.In Scenario I, we observed multiple gas production peaks (which quite similar to 6 days production behaviour) with higher localized pressure pulses occurred due to strong gas hydrate heterogeneity. In Scenario II, this drastic change in gas production rate was not observed (due to faster pressure evolution in the reservoir). In both Scenarios, the overall reservoir gas production peak is delayed compared to the homogeneous case. This is further delayed by the role of geomechanics. More interestingly, all simulation cases show a very similar overall production trend. This is probably a unique for the Mallik gas hydrate production using single vertical well, including a gas production peak but terminating in a stabilized period of lower but significant gas production.With geomechanics, gas production in general and the gas production peak is shifted and delayed. The geomechanics effect is not purely compaction drive (as in conventional reservoirs, gas production increases with geomechanics). The simulations utilized two set of geomechanical parameters obtained from logs (dynamic parameters) and rocks testing (static parameters). Geomechanical responses based on dynamic parameters were essentially equivalent to simulations ignoring geomechanical effects. The geomechanics simulations indicate an essentially elastic reservoir response (i.e. no plastic failure) assuming a cased vertical well. The Mallik upper zone A and middle zone B are closer to the permafrost and nearer to plasticity limits should be explored. © 2014 . 2014 English 18755100 10.1016/j.jngse.2014.07.002 Journal of Natural Gas Science and Engineering 20 Elsevier B.V. 250-270 Alberta Innovates - Technology Futures, Edmonton, AB T6N 1E4, Canada; Geological Survey of Canada, Natural Resources Canada, Sidney, BC V8L 4B2, Canada; Computer Modeling Group Ltd., Calgary, AB T2L 2A6, Canada Digital storage; Dissociation; Failure (mechanical); Gas industry; Gases; Geomechanics; Geophysical prospecting; Hydration; Seismic response; Seismic waves; Well logging; Well testing, Depressurizations; Dynamic parameters; Gas-hydrate production; Hydrate dissociation; Hydrate distribution; Seismic; Seismic information; Simulation, Gas hydrates https://www.scopus.com/inward/record.uri?eid=2-s2.0-84904871897&doi=10.1016%2fj.jngse.2014.07.002&partnerID=40&md5=9f0f83dec43cbf2c6451a12199a41c02 cited By 10 M. Uddin F. Wright S. Dallimore D. Coombe article Zagórski2013452 Unconventional hydrocarbon resources in last years draw the attention of petroleum geologists. Significant position take the gas hydrates, first of all due to occurrences in many regions of the world and the size of the potential resources. These accumulations are localized in Arctic regions with permafrost as well as offshore. First gas hydrate discovery occurred in Siberian gas field Messoyakha in permafrost zone and similar accumulations were found in Alaska. Offshore occurrences are located mainly on continental slope. Drillings and samples from permafrost and seabed provided vast amount of data concerned conditions of gas hydrates formation and concentration and allow to better constrain the volume of hydrate-bearing sediments and their gas yield. Resources of hydrocarbons contained in gas hydrate deposits represent a vast energy source potential. Still essential problem is to elaborate efficient commercial production technology. So far positive developments regard only laboratory or semi-commercial scale. 2013 Polish 00332151 Przeglad Geologiczny 61 Polish Geological Institute 452-459 not available, Ul. Czerniakowska 28a, m. 4, 00-714 Warszawa, Poland 8 continental slope; fossil fuel; gas field; gas hydrate; hydrocarbon resource; methane; mud volcano; permafrost; submarine landslide, Alaska; Arctic; China; Kuparuk River; Nankai; Siberia; Tianjin; United States https://www.scopus.com/inward/record.uri?eid=2-s2.0-84884824329&partnerID=40&md5=8577ea9ae29f04cba7013830cf4a63e3 cited By 2 J. Zagórski article Bellefleur2013556 The Mackenzie Delta in Canada's Northwest Territories hosts many permafrost-related gas-hydrate accumulations that were indirectly discovered or inferred from conventional hydrocarbon exploration programs. In particular, gas-hydrate intervals characterized with high saturation show high resistivity and high P-and S-wave velocity on well-log data, are typically found in sand-rich horizons. The acoustic impedance contrast between nonhydrate and hydrate-bearing sediments usually produces strong amplitude reflections on seismic data. Such a signature was previously observed onshore at Mallik, Northwestern Territories (Collett et al., 1999), on the North Slope of Alaska (Collett et al., 2011). Here, we use 2D and 3D seismic reflection data acquired by industry on Richards Island to map and characterize gas-hydrate accumulations beneath a thick permafrost area of the Mackenzie Delta (Figure 1). Specifically, we show new seismic evidences of gas-hydrate accumulations above the Ya Ya and Umiak conventional gas fields. © 2013 by The Society of Exploration Geophysicists. 2013 English 1070485X 10.1190/tle32050556.1 Leading Edge 32 Society of Exploration Geophysicists 556-563 Geological Survey of Canada, Canada 5 Acoustic impedance; Gases; Hydration; Permafrost; Petroleum prospecting; Seismic prospecting; Seismic waves; Seismology; Shear waves; Wave propagation; Well logging, Conventional hydrocarbons; High resistivity; Hydrate accumulations; Hydrate bearing sediments; North Slope of Alaska; P- and S-wave velocities; Permafrost area; Seismic evidence, Gas hydrates, detection method; gas hydrate; hydrocarbon exploration; permafrost; S-wave; seismic data; seismic reflection; well logging, Alaska; Canada; Mackenzie Delta; North Slope; Northwest Territories; Northwest Territories; Richards Island; United States https://www.scopus.com/inward/record.uri?eid=2-s2.0-84879617165&doi=10.1190%2ftle32050556.1&partnerID=40&md5=1d9e547478136f3699951306262c4d12 cited By 0 G. Bellefleur M. Riedel T. Brent article Dubreuil-Boisclair20121076 Gas hydrates located offshore and onshore beneath thick permafrost areas constitute one of the largest untapped natural gas resources. Yet, gas hydrate in place (GHIP) estimation at the scale of a field is not common in the scientific literature but is required to realistically assess the economical potential of specific accumulations. Progress in the last decade in Alaska and Canada has shown that gas hydrate accumulations beneath thick permafrost can be mapped at depth using conventional seismic attributes (Inks et al., 2009; Riedel et al. 2009). To evaluate the economic potential of gas hydrates in this environment, a test site at Mallik, Northwest Territories, Canada, was extensively surveyed (three-dimensional seismic, full set of logs in two wells, etc.) and a production test was realized in high gas-hydrate horizons. At Mallik, high P- and S-wave velocities, high acoustic impedances, and strong seismic amplitude reflections were all linked to sand-rich sediments with a high saturation of gas hydrates (Bellefleur et al. 2006; Riedel et al.). This relationship provides a strong basis for an integrated data characterization of this gas hydrate deposit. © 2012 Society of Exploration Geophysicists. 2012 English 1070485X 10.1190/tle31091076.1 Leading Edge 31 Society of Exploration Geophysicists 1076-1081 INRS-ETE, Canada; Geological Survey of Canada, Canada; Ecole Polytechnique de Montréal, Canada 9 Acoustic impedance; Energy resources; Gases; Hydration; Natural gas; Natural gas deposits; Offshore oil well production; Permafrost; Petroleum deposits; Seismic prospecting; Seismology; Shear waves; Stochastic systems, Connectivity analysis; Economic potentials; Hydrate accumulations; Natural gas resources; P- and S-wave velocities; Scientific literature; Seismic amplitudes; Volume estimations, Gas hydrates, connectivity; estimation method; gas hydrate; natural gas; permafrost; S-wave; stochasticity, Alaska; Canada; Northwest Territories; United States https://www.scopus.com/inward/record.uri?eid=2-s2.0-84872028634&doi=10.1190%2ftle31091076.1&partnerID=40&md5=4247e306f1479687f167ed19d2a86ae7 cited By 2 C. Dubreuil-Boisclair E. Gloaguen G. Bellefleur D. Marcotte article Dubreuil-Boisclair201220 For the past decades, gas hydrate reservoirs have beneficiated from an increasing attention in the academic and industrial worlds. As a result, there is a growing need to develop specific and comprehensive gas hydrate reservoir characterization methods. This study explores the use of a stochastic Bayesian algorithm to integrate well-logs and 3D acoustic impedance in order to estimate gas hydrate grades (product of saturation and total porosity) over a representative volume of the Mallik gas hydrate field, located in the Mackenzie Delta, Northwest Territories of Canada. First, collocated log data from boreholes Mallik 5L-38 and 2L-38 are used to estimate the statistical relationship between acoustic impedance and gas hydrate grades. Second, conventional stochastic Bayesian simulation is applied to generate multiple gas hydrate grade 3D fields integrating log data and lateral variability of 3D acoustic impedance. These equiprobable scenarios permit to quantify the uncertainty over the estimation, and identify zones where this uncertainty is greater. Contrary to conventional stochastic reservoir modeling workflows, the proposed method allows integrating non Gaussian and non linear distributions. This permits to handle bimodal distributions without using complex stochastic transforms. The results present gas hydrate grade values that are in accordance with well-log data. The relatively low standard deviation calculated at each pixel using all realizations suggests that gas hydrate grades is well explained by acoustic impedance and log data. © 2012 Elsevier Ltd. 2012 English 02648172 10.1016/j.marpetgeo.2012.02.020 Marine and Petroleum Geology 35 20-27 INRS-Centre Eau Terre Environnement, 490, rue de la Couronne, Québec, QC, G1K 9A9, Canada; Geological Survey of Canada, 615 Booth Street, Ottawa, ON, K1A 0E9, Canada; Dept. C.G.M. Ecole Polytechnique de Montréal, CP 6079 succ. centre-ville, Montréal, QC, H3C 3A7, Canada 1 Bayesian algorithms; Bayesian simulation; Bimodal distribution; Gas hydrate reservoir; Log data; Non-Gaussian; Non-linear distribution; Reservoir modeling; Standard deviation; Statistical relationship; Stochastic simulations; Total porosity; Well log data; Work-flows, Acoustic impedance; Estimation; Gases; Hydration; Stochastic models; Stochastic systems; Three dimensional; Three dimensional computer graphics; Well logging, Gas hydrates, acoustics; Bayesian analysis; borehole; gas field; gas hydrate; pixel; stochasticity; well logging, Canada; Mackenzie Delta; Northwest Territories https://www.scopus.com/inward/record.uri?eid=2-s2.0-84861706132&doi=10.1016%2fj.marpetgeo.2012.02.020&partnerID=40&md5=30e25bab92771cdb07c078ff68eaa438 cited By 34 C. Dubreuil-Boisclair E. Gloaguen G. Bellefleur D. Marcotte article Majorowicz2012667 Atmospheric methane from episodic gas hydrate (GH) destabilization, the "clathrate gun" hypothesis, is proposed to affect past climates, possibly since the Phanerozoic began or earlier. In the terrestrial Beaufort-Mackenzie Basin (BMB), GHs occur commonly below thick ice-bearing permafrost (IBP), but they are rare within it. Two end-member GH models, where gas is either trapped conventionally (Case 1) or where it is trapped dynamically by GH formation (Case 2), were simulated using profile (1-D) models and a 14 Myr ground surface temperature (GST) history based on marine isotopic data, adjusted to the study setting, constrained by deep heat flow, sedimentary succession conductivity, and observed IBP and Type I GH contacts in Mallik wells. Models consider latent heat effects throughout the IBP and GH intervals. Case 1 GHs formed at ∼0.9 km depth only ∼1 Myr ago by in situ transformation of conventionally trapped natural gas. Case 2 GHs begin to form at ∼290-300 m ∼6 Myr ago in the absence of lithological migration barriers. During glacial intervals Case 2 GH layers expand both downward and upward as the permafrost grows downward through and intercalated with GHs. The distinctive model results suggest that most BMB GHs resemble Case 1 models, based on the observed distinct and separate occurrences of GHs and IBP and the lack of observed GH intercalations in IBP. Case 2 GHs formed >255 m, below a persistent ice-filled permafrost layer that is as effective a seal to upward methane migration as are Case 1 lithological seals. All models respond to GST variations, but in a delayed and muted manner such that GH layers continue to grow even as the GST begins to increase. The models show that the GH stability zone history is buffered strongly by IBP during the interglacials. Thick IBP and GHs could have persisted since ∼1.0 Myr ago and ∼4.0 Myr ago for Cases 1 and 2, respectively. Offshore BMB IBP and GHs formed terrestrially during Pleistocene sea level low stands. Where IBP is sufficiently thick, both IBP and GHs persist even where inundated by a Holocene sea level rise and both are also expected to persist into the next glacial even if atmospheric CO2 doubles. We do not address the "clathrate gun" hypothesis directly, but our models show that sub-IBP GHs respond to, rather than cause GST changes, due to both how GST changes propagates with depth and latent heat effects. Models show that many thick GH accumulations are prevented from contributing methane to the atmosphere, because they are almost certainly trapped below either ice-filled IBP or lithological barriers. Where permafrost is sufficiently thick, combinations of geological structure, thermal processes and material properties make sub-IBP GHs unlikely sources for significant atmospheric methane fluxes. Our sub-IBP GH model histories suggest that similar models applied to other GH settings could improve the understanding of GHs and their potential to affect climate. © 2012 Author(s). 2012 English 18149324 10.5194/cp-8-667-2012 Climate of the Past 8 667-682 Department of Physics, University of Alberta, NGC 105 Carlson Close, Edmonton, AB, T6R 2J8, Canada; Institute of Geophysics, Czech Academy of Sciences, 141-31 Praha 4, Czech Republic; Geological Survey of Canada 3303, 33rd St. NW, Calgary, AB, T2L2A7, Canada 2 carbon dioxide; climate variation; gas hydrate; heat flux; Holocene; interglacial; lithology; methane; natural gas; paleoatmosphere; paleoclimate; permafrost; Phanerozoic; sea level change; surface temperature, Arctic Ocean; Beaufort Sea; Beaufort-Mackenzie Basin; Canada; Canadian Arctic, Calluna vulgaris https://www.scopus.com/inward/record.uri?eid=2-s2.0-84859333031&doi=10.5194%2fcp-8-667-2012&partnerID=40&md5=39cfa92bb4aae9dd116a0b4500b8e057 cited By 14 J. Majorowicz J. Šafanda K. Osadetz article Huang201283 We present a conditional simulation algorithm to parameterize three-dimensional heterogeneities and construct heterogeneous petrophysical reservoir models. The models match the data at borehole locations, simulate heterogeneities at the same resolution as borehole logging data elsewhere in the model space, and simultaneously honor the correlations among multiple rock properties. The model provides a heterogeneous environment in which a variety of geophysical experiments can be simulated. This includes the estimation of petrophysical properties and the study of geophysical response to the heterogeneities. As an example, we model the elastic properties of a gas hydrate accumulation located at Mallik, Northwest Territories, Canada. The modeled properties include compressional and shear-wave velocities that primarily depend on the saturation of hydrate in the pore space of the subsurface lithologies. We introduce the conditional heterogeneous petrophysical models into a finite difference modeling program to study seismic scattering and attenuation due to multi-scale heterogeneity. Similarities between resonance scattering analysis of synthetic and field Vertical Seismic Profile data reveal heterogeneity with a horizontal-scale of approximately 50. m in the shallow part of the gas hydrate interval. A cross-borehole numerical experiment demonstrates that apparent seismic energy loss can occur in a pure elastic medium without any intrinsic attenuation of hydrate-bearing sediments. This apparent attenuation is largely attributed to attenuative leaky mode propagation of seismic waves through large-scale gas hydrate occurrence as well as scattering from patchy distribution of gas hydrate. © 2011 Elsevier B.V.. 2012 English 09269851 10.1016/j.jappgeo.2011.12.002 Journal of Applied Geophysics 77 83-96 University of Toronto, 60 St. George Street, Toronto ON M5S 1A7, Canada; Geological Survey of Canada, 615 Booth Street, Ottawa ON K1A 0E9, Canada Borehole logging; Compressional; Conditional simulations; Distribution of gas; Elastic medium; Elastic properties; Finite-difference modeling; Gas hydrate reservoir; Heterogeneous environments; Heterogeneous rocks; Hydrate accumulations; Leaky modes; Model spaces; Multiscales; Numerical experiments; Petrophysical; Petrophysical models; Petrophysical properties; Pore space; Reservoir models; Resonance scattering; Rock properties; Seismic energy; Shear-wave velocity; Subsurface lithology; Vertical seismic profiles, Anoxic sediments; Energy dissipation; Experiments; Gases; Hydration; Petroleum reservoirs; Scattering; Seismic waves; Seismology; Shear flow; Three dimensional, Gas hydrates, algorithm; borehole logging; computer simulation; elastic property; gas hydrate; heterogeneous medium; rock property; S-wave; saturation; seismic attenuation; seismic data; three-dimensional modeling; wave propagation; wave scattering; wave velocity, Canada; Northwest Territories https://www.scopus.com/inward/record.uri?eid=2-s2.0-84855252442&doi=10.1016%2fj.jappgeo.2011.12.002&partnerID=40&md5=fd403a1857c8b0848e3227e48b5048af cited By 6 J.W. Huang G. Bellefleur B. Milkereit article Wilson2011460 A series of gas hydrate development scenarios were created to assess the range of outcomes predicted for the possible development of the "Eileen" gas hydrate accumulation, North Slope, Alaska. Production forecasts for the "reference case" were built using the 2002 Mallik production tests, mechanistic simulation, and geologic studies conducted by the US Geological Survey. Three additional scenarios were considered: A "downside-scenario" which fails to identify viable production, an "upside-scenario" describes results that are better than expected. To capture the full range of possible outcomes and balance the downside case, an "extreme upside scenario" assumes each well is exceptionally productive.Starting with a representative type-well simulation forecasts, field development timing is applied and the sum of individual well forecasts creating the field-wide production forecast. This technique is commonly used to schedule large-scale resource plays where drilling schedules are complex and production forecasts must account for many changing parameters. The complementary forecasts of rig count, capital investment, and cash flow can be used in a pre-appraisal assessment of potential commercial viability.Since no significant gas sales are currently possible on the North Slope of Alaska, typical parameters were used to create downside, reference, and upside case forecasts that predict from 0 to 71 BM3 (2.5 tcf) of gas may be produced in 20 years and nearly 283 BM3 (10 tcf) ultimate recovery after 100 years.Outlining a range of possible outcomes enables decision makers to visualize the pace and milestones that will be required to evaluate gas hydrate resource development in the Eileen accumulation. Critical values of peak production rate, time to meaningful production volumes, and investments required to rule out a downside case are provided. Upside cases identify potential if both depressurization and thermal stimulation yield positive results. An "extreme upside" case captures the full potential of unconstrained development with widely spaced wells. The results of this study indicate that recoverable gas hydrate resources may exist in the Eileen accumulation and that it represents a good opportunity for continued research. © 2010 Elsevier Ltd. 2011 English 02648172 10.1016/j.marpetgeo.2010.03.007 Marine and Petroleum Geology 28 460-477 Ryder Scott Company, L.P, 621 17th Street, Suite 1550, Denver, CO 80293, United States; ASRC Energy Services, 3900 C Street, Suite 702, Anchorage, AK 99503, United States; US Geological Survey Denver Federal Center, MS-939 Box 25046, Denver, CO 80225, United States; RPS Energy Canada, 1400, 800 Fifth Ave. SW, Calgary, AB, T2P 3T6, Canada; National Energy Technology Laboratory, 3610 Collins Ferry Road, Morgantown, WV 26507, United States; West Virginia University, Department of Chemical Engineering, Morgantown, WV 26506, United States 2 Alaska North Slope; Capital investment; Cash flow; Changing parameter; Commonly used; Critical value; Decision makers; Depressurizations; Development scenarios; Field development; Gas-hydrate production; Hydrate accumulations; North Slope of Alaska; Production forecasting; Production forecasts; Production rates; Production test; Production volumes; Resource development; Thermal stimulation; US Geological Survey, Forecasting; Gases; Hydration; Investments; Rating, Gas hydrates, forecasting method; gas hydrate; gas production; hydrocarbon reservoir; modeling; resource development, Alaska; North Slope; United States https://www.scopus.com/inward/record.uri?eid=2-s2.0-78651467241&doi=10.1016%2fj.marpetgeo.2010.03.007&partnerID=40&md5=90e03f5482e5213a8dd05880bad7bac5 cited By 38 S.J. Wilson R.B. Hunter T.S. Collett S. Hancock R. Boswell B.J. Anderson article Byun201159 Q-factor (or Q) that quantifies the attenuation, the intrinsic property of the material, is a very important required factor in extracting useful subsurface material properties such as lithological information, porosity, permeability, viscosity, and the degree of the saturation from the seismic data. When seismic energy propagates through the gas hydrate-bearing zone and a free gas layer below it, the considerable attenuation occurs and affects the amplitude and wavelet shape of recorded seismic data. Thus Q- factor extracted from seismic data can be used to locate the gas hydrate bearing zone and estimate its reserves. The spectral-ratio method has been widely used in computing the frequency-independent Q's from the zero-offset VSP data because of its ease and fastness. We developed a module of the spectral ratio method, and applied it to the synthetic zero-offset VSP data set and field zero-offset VSP data set. The field data were acquired at Mallik 3L-38 gas hydrate research well in Canada. The Q-factors calculated from the synthetic zero-offset VSP data using the spectral ratio method approached closer to the true values for the medium with low Q-factor than high Q-factor. The changes in the Q-factors extracted from the Mallik zero-offset data using the spectral ratio method agreed well with the boundaries of the layers, including gas hydrate zone, depicted in a reflection image. © 2011 Taylor & Francis Group, LLC. 2011 English 12269328 10.1080/12269328.2011.10541331 Geosystem Engineering 14 59-64 Department of Natural Resources and Geoenvironmental Engineering, Hanyang University, Seoul, South Korea; Petroleum and Marine Research Division, Korea Institute of Geoscience and Mineral Resources, Daejeon, South Korea 2 https://www.scopus.com/inward/record.uri?eid=2-s2.0-84883445158&doi=10.1080%2f12269328.2011.10541331&partnerID=40&md5=1f23a6329b239392bc3aa25e4ec33ebb cited By 1 J. Byun D.-G. Yoo H.-Y. Lee article Ramachandran2011 A 3D seismic survey (Mallik 3D), covering 126 km2 in the Mackenzie Delta area of Canada's north, was conducted by industry in 2002. Numerous lakes and marine inundation create a complex near-surface structure in the permafrost terrain. Much of the near subsurface remains frozen but significant melt zones exist particularly from perennially unfrozen water bodies. This results in an irregular distribution of permafrost ice creating a complex pattern of low and high frequency near-surface velocity variations which induce significant traveltime distortions in surface seismic data. A high resolution 3D traveltime tomography study was employed to map the permafrost velocity structure utilizing first-arrival traveltimes picked from 3D seismic shot records. Approximately 900,000 traveltime picks from 3167 shots were used in the inversion. Tomographic inversion of the first-arrival traveltimes resulted in a smooth velocity model for the upper 200 m of the subsurface. Ray coverage in the model is excellent down to 200 m providing effective control for estimating velocities through tomographic inversion. Resolution tests conducted through horizontal and vertical checkerboard tests confirm the robustness of the velocity model in detailing small scale velocity variations. Well velocities were used to validate tomographic velocities. The tomographic velocities do not show systematic correlation with well velocities. The velocity model clearly images the permafrost velocity structure in lateral and vertical directions. It is inferred from the velocity model that the permafrost structure in the near subsurface is discontinuous. Extensions of surface water bodies in depth, characterized by low P-wave velocities, are well imaged by the velocity model. Deep lakes with unfrozen water, inferred from the tomographic velocity model, correlate with areas of strong amplitude blanking and frequency attenuation observed in processed reflection seismic stack sections. © 2011 Society of Exploration Geophysicists. 2011 English 00168033 10.1190/geo2010-0353.1 Geophysics 76 Society of Exploration Geophysicists B187-B198 The University of Tulsa, Department of Geosciences, Tulsa, OK, United States; Geological Survey of Canada, Ottawa, ON, Canada; Geological Survey of Canada, Calgary, AB, Canada; Geological Survey of Canada, Sidney, BC, Canada 5 Lakes; Permafrost; Seismic prospecting; Seismic waves; Seismology; Surface structure; Tomography, Case history; Complex near surfaces; Frequency attenuation; Low and high frequencies; Systematic correlation; Tomographic inversion; Travel time tomography; Velocity analysis, Velocity, arrival time; imaging method; P-wave; permafrost; seismic data; seismic survey; seismic tomography; three-dimensional modeling; travel time; velocity structure, Canada; Mackenzie Delta; Northwest Territories https://www.scopus.com/inward/record.uri?eid=2-s2.0-84857240045&doi=10.1190%2fgeo2010-0353.1&partnerID=40&md5=38faf51d9fbce456b2c238653d17b377 cited By 14 K. Ramachandran G. Bellefleur T. Brent M. Riedel S. Dallimore article Uddin201170 Gas hydrates are a potentially vast untapped source of natural gas. Recent numerical and field studies suggest the Mallik gas-hydrate field in Canada's Mackenzie Delta may represent a technically producible and potentially economically viable reservoir of natural gas. Our initial reservoir simulations using a kinetic reaction approach indicate that gas evolution and transport within porous geologic reservoirs have a significant effect on fluid production characteristics, while field and laboratory data suggest that significant amounts of evolved gas can be trapped for some time within the reservoir, depending on the field operation. In this work, we invoke modelling concepts extensively employed in quantifying gas ex-solution from viscous oils to further assess the kinetic behaviour of gas-hydrate ex-solution through depressurization. Here, the gas bubbles can be categorized into three groups with explicit transport behaviour: small bubbles (water phase), large bubbles (immobile) and connected bubbles (or free gas). These concepts allow the development of a new set of kinetic reactions for hydrate dissociation: one representing the (possibly delayed) conversion of hydrate into water and dispersed gas bubble phases, and one representing the evolution from dispersed bubbles to connected bubbles. These reactions can effectively capture the nonequilibrium fluidflow behaviour observed in field production tests. For modelling of the transport phenomenon, we assumed two explicit mobility formulations: (1) trapped bubbles (no mobility) and a flowing water phase and (2) large connected gas bubbles and flowing water (with relative mobility). Relative mobility can be estimated by using traditional gridblock-relative permeability curves. We then develop a simple mechanistic gas bubble trapping tool as a function of the capillary number, which can easily be incorporated into our numerical simulator. This entrapment of the nonwetting gas-phase results in higher values of critical gas saturation. Two case studies based on alternative representations of a Mallik-like gas-hydrate reservoir demonstrate that significant errors can result in reservoir modelling if these fluid transport phenomena are not adequately represented in numerical simulations. Aspects of the model developed here have been applied to history matching and prediction of natural gas recovery from a clastic, sand-dominated reservoir at the Mallik site. 2011 English 00219487 10.2118/137439-pa Journal of Canadian Petroleum Technology 50 Society of Petroleum Engineers (SPE) 70-88 Alberta Innovates-Technology Futures, Canada; Geological Survey of Canada, Natural Resources Canada, Canada; Computer Modelling Group. Ltd., Canada 1 Bubbles (in fluids); Gas hydrates; Gas oils; Gases; Hydration; Kinetics; Natural gas; Natural gasoline plants; Petroleum reservoirs; Transport properties, Critical gas saturation; Gas hydrate reservoir; Hydrate dissociation; Natural gas hydrate reservoir; Natural gas recoveries; Numerical simulators; Relative permeability curves; Reservoir simulation, Natural gas fields https://www.scopus.com/inward/record.uri?eid=2-s2.0-79551698525&doi=10.2118%2f137439-pa&partnerID=40&md5=38b246105db3719af37fbc2e94be23b0 cited By 21 M. Uddin F. Wright D. Coombe article Collett2011279 In the 1960s Russian scientists made what was then a bold assertion that gas hydrates should occur in abundance in nature. Since this early start, the scientific foundation has been built for the realization that gas hydrates are a global phenomenon, occurring in permafrost regions of the arctic and in deep water portions of most continental margins worldwide. In 1995, the U.S. Geological Survey made the first systematic assessment of the in-place natural gas hydrate resources of the United States. That study suggested that the amount of gas in the gas hydrate accumulations of northern Alaska probably exceeds the volume of known conventional gas resources on the North Slope. Researchers have long speculated that gas hydrates could eventually become a producible energy resource, yet technical and economic hurdles have historically made gas hydrate development a distant goal. This view began to change in recent years with the realization that this unconventional resource could be developed with existing conventional oil and gas production technology. One of the most significant developments was the completion of the BPXA-DOE-USGS Mount Elbert Gas Hydrate Stratigraphic Test Well on the Alaska North Slope, which along with the Mallik project in Canada, have for the first time allowed the rational assessment of gas hydrate production technology and concepts. Almost 40 years of gas hydrate research in northern Alaska has confirmed the occurrence of at least two large gas hydrate accumulations on the North Slope. We have also seen in Alaska the first ever assessment of how much gas could be technically recovered from gas hydrates. However, significant technical concerns need to be further resolved in order to assess the ultimate impact of gas hydrate energy resource development in northern Alaska. © 2009 Elsevier Ltd. 2011 English 02648172 10.1016/j.marpetgeo.2009.12.001 Marine and Petroleum Geology 28 279-294 Energy Resources Program, U.S. Geological Survey, Denver Federal Center, MS-939, Box 25046, Denver, CO 80225, United States; U.S. Department of Energy, National Energy Technology Laboratory, Morgantown, WV 26507, United States; IS Interpretation Services, Inc., 1600 Stout Street, Suite 1520, Denver, CO 80202, United States 2 Alaska; Coring; Exploration; Petroleum systems; Resources; Seismic analysis, Energy resources; Gases; Hydration; Natural gas; Natural gas deposits; Natural gas well completion; Natural gas well drilling; Offshore oil wells; Permafrost; Petroleum deposits; Petroleum prospecting; Production; Rating; Resource valuation; Seismology; Stratigraphy, Gas hydrates, core logging; drilling; gas hydrate; gas production; hydrocarbon exploration; hydrocarbon generation; hydrocarbon resource; hydrocarbon technology; natural gas; permafrost, Alaska; North Slope; United States https://www.scopus.com/inward/record.uri?eid=2-s2.0-78651429017&doi=10.1016%2fj.marpetgeo.2009.12.001&partnerID=40&md5=50ee82dfb29131376801d1df02d7c6da cited By 192 T.S. Collett M.W. Lee W.F. Agena J.J. Miller K.A. Lewis M.V. Zyrianova R. Boswell T.L. Inks article Collett20101151 It is generally accepted that the amount of gas in the world's gas hydrate accumulations exceeds the volume of known conventional gas resources. Researchers have long speculated that gas hydrates could eventually be a commercial producible energy resource yet technical and economic hurdles have historically made gas hydrate development a distant goal rather than a near-term possibility. This view began to change in recent years with the realization that this unconventional resource could possibly be developed with existing conventional oil and gas production technology. The most significant development has been gas hydrate production testing conducted at the Mallik site in Canada's Mackenzie Delta. The Mallik Gas Hydrate Production Research Well Program has yielded the first modern, fully integrated field study and production test of a natural gas hydrate accumulation. More recently, BP Exploration (Alaska) Inc. with the US Department of Energy and the US Geological Survey have successfully cored, logged and tested a gas hydrate accumulation on the North Slope of Alaska known as the Mount Elbert Prospect. The Mallik project along with the Mount Elbert effort has for the first time allowed the rational assessment of the production response of a gas hydrate accumulation. In addition to the gas hydrate production tests in Canada and the USA, marine gas hydrate research drilling, coring and logging expeditions launched by the national gas hydrate programmes in Japan, India, China and South Korea have also contributed significantly to our understanding of how gas hydrates occur in nature and have provided a much deeper appreciation of the geological controls on the occurrence of gas hydrates. With an increasing number of highly successful gas hydrate field studies, significant progress has been made in addressing some of the key issues on the formation, occurrence and stability of gas hydrates in nature. © Petroleum Geology Conferences Ltd. Published by the Geological Society, London. 2010 English 20479921 10.1144/0071151 Petroleum Geology Conference Proceedings 7 1151-1154 US Geological Survey, Denver Federal Center, MS-939, Box 25046, Denver, CO 80225, United States https://www.scopus.com/inward/record.uri?eid=2-s2.0-80052533658&doi=10.1144%2f0071151&partnerID=40&md5=53febe98c1a1e1a51107f2797aefc727 cited By 3 T.S. Collett article Birchwood201018 International efforts and advanced techniques are being used to characterize properties and distributions of gas hydrates, which are crystalline solids that resemble ice. The Minerals Management Service (MMS) of the US Department of the Interior has used seismic data, along with wellbore, geologic, geochemical and paleontological information, to assess large areas of the Gulf of Mexico, where pressure and temperature conditions are suitable for hydrate-stability conditions. The team members acquired and analyzed seismic data, selected drilling locations and conducted a 35-day drilling, coring and logging expedition covering several sites. A new program was initiated in 2002 from the Mallik field to conduct production testing of gas hydrates. The USGS has studied gas hydrate accumulations in the Alaska North Slope and estimates that they contain between 25.2 and 157.8 Tcf of undiscovered recoverable natural gas. 2010 English 09231730 Oilfield Review 22 18-33 US Department of Energy, National Energy Technology Laboratory, Morgantown, WV, United States; US Geological Survey, Denver CO, United States; Lamont-Doherty Earth Observatory, Earth Institute of Columbia University, Palisades, NY, United States; Geological Survey of Canada, Sidney, BC, Canada; Japan Oil, Gas and Metals, National Corporation Chiba City, Chiba, Japan 1 Crystalline solids; Gulf of Mexico; Hydrate accumulations; Minerals management services; Pressure and temperature; Production testing; Seismic datas; Team members; Wellbore, Exploratory geochemistry; Gases; Hydration; Natural gas well drilling; Offshore oil wells; Seismic response; Seismic waves; Software testing; Well drilling, Gas hydrates https://www.scopus.com/inward/record.uri?eid=2-s2.0-79958810900&partnerID=40&md5=8b6da24e8b08b3a19de97c5f873f3013 cited By 44 R. Birchwood J. Dai D. Shelander R. Boswell T. Collett A. Cook S. Dallimore K. Fujii Y. Imasato M. Fukuhara K. Kusaka D. Murray T. Saeki article Riedel2009 We combine acoustic impedance inversion of 3D seismic data, log-to-seismic correlation, and seismic attribute analyses to delineate gas-hydrate zones at the Mallik site, Mackenzie Delta, Northwest Territories, Canada. Well-log data define three distinct hydrate zones over a depth range of 890-1100 m. Synthetic seismic modeling indicates the base of the two deeper hydrate zones are prominent reflectors. The uppermost gas-hydrate zone correlates to seismic data with a lower degree of confidence. The extent and geometry of the two lower hydrate zones suggest that local geology plays a significant role in the lateral and vertical distribution of gas hydrate at Mallik. The reliability of the hydrate concentrations calculated from the inverted impedances isqualified by the match between original and synthetic seismic data to produce confidence maps for the two lower gas-hydrate-bearing intervals. A total in-place volume estimate of solid gas hydrate for an area of 1.44 km2 around well 5L-38 yields a value of approximately 45 × 106m3 (equivalently, 6.6 × 109m3 of gas). We further qualify our mapping of gas hydrates by some amount of continuous resource, defined as lateral continuity measured by seismic attribute similarity and sand-dominated rock. Using these attributes, the continuous amount of hydrate at Mallik is about half the in-place volume (i.e., 25 × 106 m3). Elsewhere within the 3D seismic cube, the seismic impedance inversion yields evidence of potential gas-hydrate deposits near wells A-06 and P-59 at levels near the predicted base of the hydrate stability zone. © 2009 Society of Exploration Geophysicists. All rights reserved. 2009 English 00168033 10.1190/1.3159612 GEOPHYSICS 74 Society of Exploration Geophysicists B125-B137 McGill University, Department of Earth and Planetary Sciences, Montreal, QC, Canada; Geological Survey of Canada, Ottawa, ON, Canada; Geological Survey of Canada, Calgary, AB, Canada; Geological Survey of Canada, Sidney, BC, Canada 5 Acoustic impedance; Gases; Geophysical prospecting; Hydration; Seismic response; Seismic waves; Well logging, Acoustic impedance inversion; Degree of confidence; Hydrate concentration; Hydrate stabilities; Seismic attribute analysis; Seismic attributes; Seismic reflections; Vertical distributions, Gas hydrates, acoustic data; conference proceeding; confidence interval; gas field; gas hydrate; gas well; hydrocarbon resource; seismic data; seismic reflection; spatial distribution; three-dimensional modeling; well logging, Canada; Mackenzie Delta; North America; Northwest Territories https://www.scopus.com/inward/record.uri?eid=2-s2.0-71049118147&doi=10.1190%2f1.3159612&partnerID=40&md5=13d0893d90bc5dfde3ec36ea7d56004f cited By 43 M. Riedel G. Bellefleur S. Mair T.A. Brent S.R. Dallimore article Rutqvist20091 In this simulation study, we analyzed the geomechanical response during depressurization production from two known hydrate-bearing permafrost deposits: the Mallik (Northwest Territories, Canada) deposit and Mount Elbert (Alaska, USA) deposit. Gas was produced from these deposits at constant pressure using horizontal wells placed at the top of a hydrate layer (HL), located at a depth of about 900 m at the Mallik site and 600 m at the Mount Elbert site. The simulation results show that general thermodynamic and geomechanical responses are similar for the two sites, but with substantially higher production and more intensive geomechanical responses at the deeper Mallik deposit. The depressurization-induced dissociation begins at the well bore and then spreads laterally, mainly along the top of the HL. The depressurization results in an increased shear stress within the body of the receding hydrate and causes a vertical compaction of the reservoir. However, its effects are partially mitigated by the relatively stiff permafrost overburden, and compaction of the HL is limited to less than 0.4%. The increased shear stress may lead to shear failure in the hydrate-free zone bounded by the HL overburden and the downward-receding upper dissociation interface. This zone undergoes complete hydrate dissociation, and the cohesive strength of the sediment is low. We determined that the likelihood of shear failure depends on the initial stress state as well as on the geomechanical properties of the reservoir. The Poisson's ratio of the hydrate-bearing formation is a particularly important parameter that determines whether the evolution of the reservoir stresses will increase or decrease the likelihood of shear failure. 2009 English 09204105 10.1016/j.petrol.2009.02.013 Journal of Petroleum Science and Engineering 67 1-12 Earth Sciences Division, Lawrence Berkeley National Laboratory, MS 90-1116, Berkeley, CA 947 20, United States; Petroleum Engineering Department, Texas A and M University, MS 3116, Richardson Building, College Station, TX 77843, United States; US Geological Survey, Denver Federal Center, P.O. Box 25046, MS-939, Denver, CO 80225, United States 1-2 Alaska , usa; Cohesive strengths; Constant pressures; depressurization; Gas productions; Geomechanical properties; geomechanics; hydrate dissociation; Induced dissociations; Initial stress state; Poisson's ratios; Reservoir stress; Shear failures; Simulation results; Simulation studies; Well bores, Bearings (structural); Compaction; Dissociation; Gases; Horizontal wells; Hydration; International trade; Oil wells; Permafrost; Poisson ratio; Shear stress; Strength of materials, Gas hydrates, computer simulation; gas hydrate; permafrost; Poisson ratio; shear stress; soil mechanics; thermodynamics https://www.scopus.com/inward/record.uri?eid=2-s2.0-67349248544&doi=10.1016%2fj.petrol.2009.02.013&partnerID=40&md5=39a8fc288d8e34726ca9c00a1e61f204 cited By 175 J. Rutqvist G.J. Moridis T. Grover T. Collett article Sun2009 No perfectly elastic medium exists in the earth. In an anelastic medium, seismic waves are distorted by attenuation and velocity dispersion. Velocity dispersion depends on the petrophysical properties of reservoir rocks, such as porosity, fractures, fluid mobility, and the scale of heterogeneities. However, velocity dispersion usually is neglected in seismic data processing partly because of the insufficiency of observations in the exploration seismic frequency band (∼5 through 200 Hz). The feasibility of determining velocity dispersion in this band is investigated. Four methods are used in measuring velocity dispersion from uncorrelated vibrator vertical seismic profile (VSP) data: the moving window crosscorrelation (MWCC) method, instantaneous phase method, time-frequency spectral decomposition method, and cross-spectrum method. The MWCC method is a new method that is satisfactorily robust, accurate, and efficient in measuring the frequency-dependent traveltime in uncorrelated vibrator records. The MWCC method is applied to the uncorrelated vibrator VSP data acquired in the Mallik gas hydrate research well. For the first time, continuous velocity dispersion is observed in the exploration seismic frequency band using uncorrelated vibrator VSP data. The observed velocity dispersion is fitted to a straight line with respect to log frequency to calculate Q. This provides an alternative method for Q measurement. © 2009 Society of Exploration Geophysicists. All rights reserved. 2009 English 00168033 10.1190/1.3068426 Geophysics 74 Society of Exploration Geophysicists WA113-WA122 University of Toronto, Department of Physics, Toronto, ON, Canada; University of Alberta, Department of Physics, Institute for Geophysical Research, Edmonton, AB, Canada 2 Data handling; Dispersion (waves); Gas hydrates; Petroleum prospecting; Petrophysics; Seismic waves; Seismology; Velocity; Vibrators, Frequency dependent; Instantaneous phase; Petrophysical properties; Seismic data processing; Seismic frequencies; Spectral decomposition methods; Velocity dispersion; Vertical seismic profiles, Seismic prospecting, accuracy assessment; conference proceeding; data processing; efficiency measurement; frequency analysis; frequency dependence; heterogeneity; observational method; seismic attenuation; seismic data; seismic velocity; seismic wave; wave dispersion https://www.scopus.com/inward/record.uri?eid=2-s2.0-63049125819&doi=10.1190%2f1.3068426&partnerID=40&md5=8814ea3823e54c6d81dcb88777f416bd cited By 36 L.F. Sun B. Milkereit article Lu2009157 Based on field-investigated gas geochemistry and predecessors data such as the permafrost ground temperature, thermal gradients within/below the frozen layer, the modeling on gas hydrate formation conditions is conducted in the Qinghai-Tibet plateau permafrost. The modeled results show that the permafrost characteristics generally meet gas hydrate formation conditions in the study area. Gas composition, temperature-related permafrost parameters (e. g. permafrost thickness or its ground temperature and thermal gradients within / below the frozen layer) are the most important factors affecting gas hydrate occurrences, whose variance may cause the heterogeneity of gas hydrate occurrences in the study area. The most probable gas hydrate is the kind of hybrid of methane and weight hydrocarbon gases (ethane and propane). In the predicted gas hydrate locations, the upper gas hydrate occurrence depth may be around several ten to more than one hundred meters and the lower depth may range from several hundred meters to about one thousand meters and the thickness may reach several hundred meters. Compared with Canadian Mallik permafrost, the Qinghai-Tibet plateau permafrost has similar thermal gradients within / below the frozen layer and gas composition, except for relatively thinner permafrost, still suggesting great gas hydrate potentials. 2009 Chinese 00015733 Acta Geophysica Sinica 52 Science Press 157-168 Institute of Mineral Resources, CAGS, Beijing 100037, China; Departement de Geosciences Marines, IFREMER, Centre de Brest, Plouzané 29280, France; Strategic Research Center for Oil and Gas Resources, Ministry of Land and Resources, Beijing 100034, China; National Center for Geological Experiment and Test, Beijing 100037, China 1 frozen ground; gas hydrate; geochemistry; heterogeneity; permafrost; temperature gradient, Asia; China; Eurasia; Far East; Qinghai-Xizang Plateau https://www.scopus.com/inward/record.uri?eid=2-s2.0-67649289954&partnerID=40&md5=d3d7b3bdff7f5f835db9594bdbb2c34a cited By 26 Z.-Q. Lu N. Sultan C.-S. Jin Z. Rao X.-R. Luo B.-H. Wu Y.-H. Zhu article Huang2009 In hydrate-bearing sediments, the velocity and attenuation of compressional and shear waves depend primarily on the spatial distribution of hydrates in the pore space of the subsurface lithologies. Recent characterizations of gas hydrate accumulations based on seismic velocity and attenuation generally assume homogeneous sedimentary layers and neglect effects from large- and small-scale heterogeneities of hydrate-bearing sediments. We present an algorithm, based on stochastic medium theory, to construct heterogeneous multivariable models that mimic heterogeneities of hydrate-bearing sediments at the level of detail provided by borehole logging data. Using this algorithm, we model some key petrophysical properties of gas hydrates within heterogeneous sediments near the Mallik well site, Northwest Territories, Canada. The modeled density, and P and S wave velocities used in combination with a modified Biot-Gassmann theory provide a first-order estimate of the in situ volume of gas hydraté near the Mallik 5L-38 borehole. Our results suggest a range of 528 to 768 × 106 m3/km2 of natural gas trapped within hydrates, nearly an order of magnitude lower than earlier estimates which did not include effects of small-scale heterogeneities. Further, the petrophysical models are combined with a 3-D finite difference modeling algorithm to study seismic attenuation due to scattering and leaky mode propagation. Simulations of a near-offset vertical seismic profile and cross-borehole numerical surveys demonstrate that attenuation of seismic energy may not be directly related to the intrinsic attenuation of hydrate-bearing sediments but, instead, may be largely attributed to scattering from small-scale heterogeneities and highly attenuate leaky mode propagation of seismic waves through larger-scale heterogeneities in sediments. Copyright 2009 by the American Geophysical Union. 2009 English 21699313 10.1029/2008JB006172 Journal of Geophysical Research: Solid Earth 114 Blackwell Publishing Ltd Department of Physics, University of Toronto, 60 Saint George Street, Toronto, ON M5S 1A7, Canada; Geological Survey of Canada, 615 Booth Street, Ottawa, ON KlA 0E9, Canada 7 borehole; fault propagation; finite difference method; gas hydrate; geoaccumulation; heterogeneity; natural gas; P-wave; reservoir; S-wave; seismic attenuation; seismic velocity; spatial distribution; stochasticity; three-dimensional modeling, Canada; North America https://www.scopus.com/inward/record.uri?eid=2-s2.0-70349687445&doi=10.1029%2f2008JB006172&partnerID=40&md5=cf122661888647d3a9513fc631a9a0ee cited By 42 J.-W. Huang G. Bellefleur B. Milkereit article Bauer2008 Crosshole seismic experiments were conducted to study the in-situ properties of gas hydrate bearing sediments (GHBS) in the Mackenzie Delta (NW Canada). Seismic tomography provided images of P velocity, anisotropy, and attenuation. Self-organizing maps (SOM) are powerful neural network techniques to classify and interpret multi-attribute data sets. The coincident tomographic images are translated to a set of data vectors in order to train a Kohonen layer. The total gradient of the model vectors is determined for the trained SOM and a watershed segmentation algorithm is used to visualize and map the lithological clusters with well-defined seismic signatures. Application to the Mallik data reveals four major litho-types: (1) GHBS, (2) sands, (3) shale/coal interlayering, and (4) silt. The signature of seismic P wave characteristics distinguished for the GHBS (high velocities, strong anisotropy and attenuation) is new and can be used for new exploration strategies to map and quantify gas hydrates. Copyright 2008 by the American Geophysical Union. 2008 English 00948276 10.1029/2008GL035263 Geophysical Research Letters 35 Section 2.2 GeoForschungsZentrum Potsdam, Telegrafenberg, D-14473 Potsdam, Germany; Department of Earth Sciences, University of Western Ontario, London, ON N6A 5B7, Canada 19 Anisotropy; Bearings (structural); Conformal mapping; Diagnostic radiography; Earthquakes; Electric network analysis; Feature extraction; Graph theory; Hydration; Image enhancement; Lithology; Medical imaging; Neural networks; Petroleum engineering; Petroleum prospecting; Sedimentology; Seismic prospecting; Seismology; Self organizing maps; Strength of materials; Tomography; Vectors, Attribute datums; Crosshole; Data vectors; Exploration strategies; High velocities; In-situ; Interlayering; Kohonen layers; Model vectors; Neural network analyses; Neural Network techniques; P velocities; P waves; Seismic signatures; Seismic tomographies; Strong anisotropies; Tomographic images; Watershed segmentation algorithms, Gas hydrates, algorithm; artificial neural network; crosshole seismic method; data set; gas hydrate; lithology; lithotype; P-wave; seismic anisotropy; seismic attenuation; seismic tomography; seismic velocity, Canada; Mackenzie Delta; North America; Northwest Territories https://www.scopus.com/inward/record.uri?eid=2-s2.0-57749189994&doi=10.1029%2f2008GL035263&partnerID=40&md5=a3bd3334ee3b432b293b53b6e5fb0def cited By 24 K. Bauer R.G. Pratt C. Haberland M. Weber article Anderson2008285 Gas hydrates, which are naturally occurring ice-like combinations of gas and water, have the potential to provide vast amounts of natural gas from the world's oceans and polar regions. However, producing gas economically from hydrates entails major technical challenges. Proposed recovery methods such as dissociating or melting gas hydrates by heating or depressurization are currently being tested. One such test was conducted in northern Canada by the partners in the Mallik 2002 Gas Hydrate Production Research Well Program. This paper describes how resistivity logs were used to determine the size of the annular region of gas hydrate dissociation that occurred around the wellbore during the thermal test in the Mallik 5L-38 well. An open-hole logging suite, run prior to the thermal test, included array induction, array laterolog, nuclear magnetic resonance and 1.1-GHz electromagnetic propagation logs. The reservoir saturation tool was run both before and after the thermal test to monitor formation changes. A cased-hole formation resistivity log was run after the test.Baseline resistivity values in each formation layer (Rt) were established from the deep laterolog data. The resistivity in the region of gas hydrate dissociation near the wellbore (Rxo) was determined from electromagnetic propagation and reservoir saturation tool measurements. The radius of hydrate dissociation as a function of depth was then determined by means of iterative forward modeling of cased-hole formation resistivity tool response. The solution was obtained by varying the modeled dissociation radius until the modeled log overlaid the field log. Pretest gas hydrate production computer simulations had predicted that dissociation would take place at a uniform radius over the 13-ft test interval. However, the post-test resistivity modeling showed that this was not the case. The resistivity-derived dissociation radius was greatest near the outlet of the pipe that circulated hot water in the wellbore, where the highest temperatures were recorded. The radius was smallest near the center of the test interval, where a conglomerate section with low values of porosity and permeability inhibited dissociation. The free gas volume calculated from the resistivity-derived dissociation radii yielded a value within 20 per cent of surface gauge measurements. These results show that the inversion of resistivity measurements holds promise for use in future gas hydrate monitoring. © 2008 Society of Petrophysicists and Well Log Analysts. All rights reserved. 2008 English 15299074 Petrophysics 49 285-294 Schlumberger, 89 Stony Hill Rd., Brookfield, CT 06804, United States; US Geological Survey, Denver Federal Center, Box 25046, Denver, CO 80225, United States; Schlumberger Oilfield Services, 5 Broadway Executive Park Building, 6601 Broadway Extension, Oklahoma City, OK 73116-8214, United States; Etudes et Productions Schlumberger, 1 rue Henri Becquerel, 92142 Clamart, Cedex, France 3 Cased-hole formation resistivity (CHFR); Depressurization; Electromagnetic propagation; Gas Hydrate production; Hydrate dissociation; logging suite; Magnetic (CE); Monitor (CO); Northern Canada; Openhole (OH); Polar Regions; Resistivity logs; Resistivity values; Technical challenges; Well bores, Density measurement (specific gravity); Dissociation; Electric logging; Electromagnetic logging; Gas industry; Gases; Hydrates; Hydration; Magnetic fields; Magnetic resonance; Magnetism; Monitoring; Nuclear magnetic logging; Nuclear magnetic resonance; Offshore oil well production; Oil well logging; Radioactivity logging; Resonance; Testing; Thermal logging; Well stimulation, Gas hydrates https://www.scopus.com/inward/record.uri?eid=2-s2.0-46449089372&partnerID=40&md5=4a66b4b0af85c5f7fac4d0e08b533a52 cited By 11 B.I. Anderson T.S. Collett R.E. Lewis I. Dubourg article Lee2008 Relating pore-space gas hydrate saturation to sonic velocity data is important for remotely estimating gas hydrate concentration in sediment. In the present study, sonic velocities of gas hydrate-bearing sands are modeled using a three-phase Biot-type theory in which sand, gas hydrate, and pore fluid form threehomogeneous, interwoven frameworks. This theory is developed using well log compressional and shear wave velocity data from the Mallik 5L-38 permafrost gas hydrate research well in Canada and applied to well log data from hydrate-bearing sands in the Alaskan permafrost, Gulf of Mexico, and northern Cascadia margin. Velocity-based gas hydrate saturation estimates are in good agreement with Nuclear Magneto Resonance and resistivity log estimates over the complete range of observed gas hydrate saturations. Copyright 2008 by the American Geophysical Union. 2008 English 15252027 10.1029/2008GC002081 Geochemistry, Geophysics, Geosystems 9 U.S. Geological Survey, Box 25046, Denver Federal Center, Denver, CO 80225, United States; U.S. Geological Survey, 384 Woods Hole Road, Woods Hole, MA 02543, United States 7 https://www.scopus.com/inward/record.uri?eid=2-s2.0-66149169413&doi=10.1029%2f2008GC002081&partnerID=40&md5=c3af352ef1eeb01b7a09a772ef401771 cited By 142 M.W. Lee W.F. Waite article Rubino2008 This paper studies the energy conversions that take place at discontinuities within gas hydrate-bearing sediments and their influence on the attenuation of waves traveling through these media. The analysis is based on a theory recently developed by some of the authors, to describe wave propagation in multiphasic porous media composed of two solids saturated by a single-phase fluid. Real data from the Mallik 5L-38 Gas Hydrate Research well are used to calibrate the physical model, allowing to obtain information about the characteristics of the cementation between the mineral grains and gas hydrates for this well. Numerical experiments show that, besides energy conversions to reflected and transmitted classical waves, significant fractions of the energy of propagating waves may be converted into slow-waves energy at plane heterogeneities within hydrated sediments. Moreover, numerical simulations of wave propagation show that very high levels of attenuation can take place in the presence of heterogeneous media composed of zones with low and high gas hydrate saturations with sizes smaller or on the order of the wavelengths of the fast waves at sonic frequencies. These attenuation levels are in very good agreement with those measured at the Mallik 5L-38 Gas Hydrate Research Well, suggesting that these scattering-type effects may be a key-parameter to understand the high sonic attenuation observed at gas hydrate-bearing sediments. Copyright 2008 by the American Geophysical Union. 2008 English 21699313 10.1029/2006JB004871 Journal of Geophysical Research: Solid Earth 113 Blackwell Publishing Ltd CONICET, Facultad de Ciencias Astronómicas y Geofisicas, Universidad Nacional de La Plata, Paseo del Bosque S/N, B1900FWA La Plata, Argentina; Department of Mathematics, Purdue University, West Lafayette, IN, United States 6 Biot theory; experimental study; gas hydrate; heterogeneous medium; numerical model; porous medium; single-phase flow; wave attenuation; wave propagation; wavelength https://www.scopus.com/inward/record.uri?eid=2-s2.0-50649120353&doi=10.1029%2f2006JB004871&partnerID=40&md5=515755fffbabad8e7c13506f32a6c7dd cited By 5 J.G. Rubino C.L. Ravazzoli J.E. Santos article Uddin20080325021 Continuing concern about the impacts of atmospheric carbon dioxide (CO 2) on the global climate system provides an impetus for the development of methods for long-term disposal of CO2 produced by industrial and other activities. Investigations of the CO2-hydrate properties indicate the feasibility of geologic sequestration CO2 as gas hydrate and the possibility of coincident CO2 sequestration/CH4 production from natural gas hydrate reservoirs. Numerical studies can provide an integrated understanding of the process mechanisms in predicting the potential and economic viability of CO2 gas sequestration, especially when utilizing realistic geological reservoir characteristics in the models. This study numerically investigates possible sequestration of CO2 as a stable gas hydrate in various reservoir geological formations. As such, this paper extends the applicability of a previously developed model to more realistic and relevant reservoir scenarios. A unified gas hydrate model coupled with a thermal reservoir simulator (CMG STARS) was applied to simulate CO2-hydrate formation in four reservoir geological formations. These reservoirs can be described as follows. The first reservoir (Reservoir I) is similar to tight gas reservoir with mean porosity 0.25 and mean absolute permeability 10 mD. The second reservoir (Reservoir II) is similar to a conventional sandstone reservoir with mean porosity 0.25 and mean permeability 20 mD. The third reservoir (Reservoir III) is similar to hydrate-free Mallik silt with mean porosity 0.30 and mean permeability 100 mD. The fourth reservoir (Reservoir IV) is similar to hydrate-free Mallik sand with mean porosity 0.35 and mean permeability 1000 mD. The Mallik gas hydrate bearing formation itself can be described as several layers of variable thickness with permeability variations from 1 mD to 1000 mD, and is addressed as a separate part of this study. This paper describes numerical methodology, model input data selection, and reservoir simulation results, including an enhancement to model the effects of ice formation and decay. The numerical investigation shows that the gas hydrate model effectively captures the spatial and temporal dynamics of CO2-hydrate formation in geological reservoirs by injection of CO2 gas. Practical limitations to CO2-hydrate formation by gas injection are identified and potential improvements to the process are suggested. Copyright © 2008 by ASME. 2008 English 01950738 10.1115/1.2956979 Journal of Energy Resources Technology, Transactions of the ASME 130 0325021-03250211 Alberta Research Council Inc., 250 Karl Clark Road, Edmonton, AB T6N 1E4, Canada; Computer Modeling Group Ltd., 3512-33 Street, NW, Calgary, AB T2L 2A6, Canada; Geological Survey of Canada, Terrain Sciences Division, Box 6000, 9860 West Saanich Road, Sidney, BC V8L 4B2, Canada 3 Atmospheric chemistry; Capillarity; Carbon dioxide; Data reduction; Gas hydrates; Gas industry; Gases; Hydration; Liquids; Numerical analysis; Petroleum reservoirs; Porosity; Solids; Water injection, CH4 hydrate; CO2 hydrate; CO2 sequestration; Geological reservoir; Hydrate decomposition; Hydrate formation; Numerical simulation, Petroleum reservoir engineering https://www.scopus.com/inward/record.uri?eid=2-s2.0-57249111695&doi=10.1115%2f1.2956979&partnerID=40&md5=03b71a72d6bed207a7862e8b1fe12c92 cited By 40 M. Uddin D. Coombe F. Wright article Dai2008830 This article presents the results of applying a five-step process for using high-quality seismic data to locate marine gas hydrates. The process involved (1) reprocessing of seismic data for higher resolution, (2) detailed stratigraphic evaluation and interpretation to locate possible hydrate-bearing zones, (3) seismic attribute analysis to further delineate these zones, (4) seismic inversion to obtain appropriate elastic parameters of these zones in 3D, and (5) quantitative estimation of gas hydrate saturation from seismic data using inversion and rock physics principles. We used seismic data from Keathley Canyon 151 and Atwater Valley 14 in the northern Gulf of Mexico. Although careful analysis did indicate the presence of a bottom simulating reflector (BSR), our study mainly relied on a host of other seismic attributes (e.g., gas chimneys, seismically transparent zones, other features associated with the petroleum system) to characterize the occurrence of gas hydrates in these areas. We tested and verified a viable rock model for hydrate-bearing sediments using data from the Mallik (McKenzie Delta, Canada) and Blake Ridge (ODP Leg 164, southeast U.S. Atlantic margin) wells and modified it for application in the current area. We then used this model to estimate gas hydrate saturation in the host sediments of the northern Gulf of Mexico focus areas using estimates of P-wave and S-wave velocities from inversion of reflection seismic data. In this paper, we present the gas hydrate saturations predicted from the seismic processing methodology prior to 2005 drilling in the focus areas. In frontier areas where no well data are available and lithologic heterogeneities are poorly understood, implementing a seismic-based technique like the one described here to identify potential gas hydrates can provide valuable pre-drill information for site selection and for planning future characterization studies of gas hydrate-bearing sediments. 2008 English 02648172 10.1016/j.marpetgeo.2008.02.006 Marine and Petroleum Geology 25 830-844 Schlumberger, 10001 Richmond, Houston, TX 77042, United States 9 Bottom simulating reflector (BSR); Gas hydrate; Gulf of Mexico; Rock physics models; Seismic inversion, Bearings (structural); Gases; Geologic models; Hydration; Modal analysis; Offshore oil well production; Offshore oil wells; Offshore petroleum prospecting; Parameter estimation; Petroleum engineering; Petroleum prospecting; Reflection; Sedimentation; Sedimentology; Seismic response; Seismic waves; Seismology; Site selection; Stratigraphy; Three dimensional, Gas hydrates, deep water; estimation method; gas hydrate; hydrocarbon exploration; hydrocarbon reservoir; inverse analysis; P-wave; S-wave; seismic data; seismic method; seismic reflection; seismic velocity; three-dimensional modeling, Atlantic Ocean; Gulf of Mexico https://www.scopus.com/inward/record.uri?eid=2-s2.0-53349165624&doi=10.1016%2fj.marpetgeo.2008.02.006&partnerID=40&md5=11098a8fd485a3e2afff2ecf952819bc cited By 93 J. Dai F. Snyder D. Gillespie A. Koesoemadinata N. Dutta article NoAuthor2008 The US Geological Survey (USGS) estimated that 85.4 tcf of methane could be trapped in these cage-like lattices of ice about 2000 ft below the permafrost. According to USGS Director Mark Myers, a growing body of evidence indicates that concentrated gas-hydrate accumulations in conventional hydrocarbons reservoirs, such as those in northern Alaska, can be produced with existing technology, particularly depressurization. This technique lowers the pressure in the well, which causes the hydrates to become unstable and dissociate into water and gas that can be pumped to the surface. The Mallik 2002 Gas Hydrate Production Research Well Program, conducted in the Mackenzie Delta, Northwest Territories, Canada, represented the first modern, fully integrated field study and production testing of a gas-hydrate accumulation. It demonstrated that methane could be produced from gas hydrates by using pressure stimulation and that combining depressurisation with heating increased gas production. Numerous technical problems must still be overcome before this potential resource can be considered economically producible. One, for example, is the risk of releasing methane into the atmosphere; this gas is about 20 times more potent than CO2 as a greenhouse gas, which contributes to global warming. However, the effort would be worthwhile. The North Slope's hydrate reserves could provide enough gas to heat 100 m homes for up to a decade. The opportunity to develop them would also provide another justification for the proposed $26 billion, 1700 mi pipeline to carry conventionally produced natural gas from the North Slope to markets in the lower 48 states. 2008 English 0306395X Petroleum Economist 75 Petroleum Economist Ltd. 12 https://www.scopus.com/inward/record.uri?eid=2-s2.0-65249130682&partnerID=40&md5=4f3b24f2ee48a3f4d670093fd05e970e cited By 0 article Lee2007 In contrast to hydrate-free sediments, sonic waveforms acquired in gas hydrate-bearing sediments indicate strong amplitude attenuation associated with a sonic velocity increase. The amplitude attenuation increase has been used to quantify pore-space hydrate content by attributing observed attenuation to the hydrate-bearing sediment's intrinsic attenuation. A second attenuation mechanism must be considered, however. Theoretically, energy radiation from sources inside fluid-filled boreholes strongly depends on the elastic parameters of materials surrounding the borehole. It is therefore plausible to interpret amplitude loss in terms of source coupling to the surrounding medium as well as to intrinsic attenuation. Analyses of sonic waveforms from the Mallik 5L-38 well, Northwest Territories, Canada, indicate a significant component of sonic waveform amplitude loss is due to source coupling. Accordingly, all sonic waveform amplitude analyses should include the effect of source coupling to accurately characterize a formation's intrinsic attenuation. 2007 English 00948276 10.1029/2006GL029015 Geophysical Research Letters 34 U.S. Geological Survey, Denver Federal Center, Box 25046, MS-939, Denver, CO 80225, United States; U.S. Geological Survey, 384 Woods Hole Road, Woods Hole, MA 02543, United States 5 Acoustic wave velocity; Boreholes; Gas hydrates; Sediments; Waveform analysis, Energy radiation; Sonic waveform, Petroleum prospecting, amplitude; pore space; seismic attenuation; sonic boom; wave velocity; waveform analysis, Canada; North America; Northwest Territories https://www.scopus.com/inward/record.uri?eid=2-s2.0-34249904890&doi=10.1029%2f2006GL029015&partnerID=40&md5=8b78445b98da9e52ae77503202c1ca86 cited By 17 M.W. Lee W.F. Waite article McGrail2007 Resonant ultrasound spectroscopy was used to characterize a natural geological core sample obtained from the Mallik 5L-38 gas hydrate research well at high pressure and subambient temperatures. Using deuterated methane gas to form gas hydrate in the core sample, it was discovered that resonance amplitudes are correlated with the fraction of the pore space occupied by the gas hydrate crystals. A pore water freezing model was developed that utilizes the known pore size distribution and pore water chemistry to predict gas hydrate saturation as a function of pressure and temperature. The model showed good agreement with the experimental measurements and demonstrated that pore water chemistry is the most important factor controlling equilibrium gas hydrate saturations in these sediments when gas hydrates are formed artificially in laboratory pressure vessels. With further development, the resonant ultrasound technique can provide a rapid, nondestructive, field portable means of measuring the equilibrium P-T properties and dissociation kinetics of gas hydrates in porous media, determining gas hydrate saturations, and may provide new insights into the nature of gas hydrate formation mechanisms in geologic materials. Copyright 2007 by the American Geophysical Union. 2007 English 21699313 10.1029/2005JB004084 Journal of Geophysical Research: Solid Earth 112 Blackwell Publishing Ltd Applied Geology and Geochemistry Department, Pacific Northwest National Laboratory, Richland, WA, United States; Applied Physics and Materials Characterization Department, Pacific Northwest National Laboratory, Richland, WA, United States; Petroleum Engineering Department, University of Alaska, Fairbanks, AK, United States; Applied Physics and Materials Characterization Department, Pacific Northwest National Laboratory, P. O. Box 999, Richland, WA 99352, United States; Applied Geology and Geochemistry Department, Pacific Northwest National Laboratory, P. O. Box 999, Richland, WA 99352, United States; Petroleum Engineering Department, University of Alaska, 411 Duckering Building, Fairbanks, AK 99775, United States 5 core analysis; equilibrium; gas hydrate; laboratory method; measurement method; pore space; porewater; porous medium; resonance; saturation; spectroscopy https://www.scopus.com/inward/record.uri?eid=2-s2.0-65349132403&doi=10.1029%2f2005JB004084&partnerID=40&md5=968aa9e186b76e43ae222d81e1cce597 cited By 2 B.P. McGrail S. Ahmed H.T. Schaef A.T. Owen P.F. Martin T. Zhu article Tomaru2007656 The authors report here halogen concentrations in pore waters and sediments collected from the Mallik 5L-38 gas hydrate production research well, a permafrost location in the Mackenzie Delta, Northwest Territories, Canada. Iodine and Br are commonly enriched in waters associated with CH4, reflecting the close association between these halogens and source organic materials. Pore waters collected from the Mallik well show I enrichment, by one order of magnitude above that of seawater, particularly in sandy layers below the gas hydrate stability zone (GHSZ). Although Cl and Br concentrations increase with depth similar to the I profile, they remain below seawater values. The increase in I concentrations observed below the GHSZ suggests that I-rich fluids responsible for the accumulation of CH4 in gas hydrates are preferentially transported through the sandy permeable layers below the GHSZ. The Br and I concentrations and I/Br ratios in Mallik are considerably lower than those in marine gas hydrate locations, demonstrating a terrestrial nature for the organic materials responsible for the CH4 at the Mallik site. Halogen systematics in Mallik suggest that they are the result of mixing between seawater, freshwater and an I-rich source fluid. The comparison between I/Br ratios in pore waters and sediments speaks against the origin of the source fluids within the host formations of gas hydrates, a finding compatible with the results from a limited set of 129I/I ratios determined in pore waters, which gives a minimum age of 29 Ma for the source material, i.e. at the lower end of the age range of the host formations. The likely scenario for the gas hydrate formation in Mallik is the derivation of CH4 together with I from the terrestrial source materials in formations other than the host layers through sandy permeable layers into the present gas hydrate zones. © 2006 Elsevier Ltd. All rights reserved. 2007 English 08832927 10.1016/j.apgeochem.2006.12.013 Applied Geochemistry 22 656-675 Department of Earth and Environmental Sciences, University of Rochester, Rochester, NY 14627, United States; Department of Earth and Planetary Science, University of Tokyo, Tokyo, 113-0033, Japan 3 Earth atmosphere; Gas hydrates; Natural gas wells; Seawater; Sedimentology, Gas hydrate production; Gas hydrate stability zone (GHSZ); Halogen systematics; Pore waters, Halogen compounds, bromine; coastal sediment; enrichment; gas hydrate; iodine; methane; mixing; organic matter; permafrost; porewater; seawater, Canada; Mackenzie Delta; North America; Northwest Territories https://www.scopus.com/inward/record.uri?eid=2-s2.0-33847332547&doi=10.1016%2fj.apgeochem.2006.12.013&partnerID=40&md5=95bf922761b1217ee1658df8cef9ae05 cited By 27 H. Tomaru U. Fehn Z. Lu R. Matsumoto article Bellefleur2007 Wave attenuation is an important physical property of hydrate-bearing sediments that is rarely taken into account in site characterization with seismic data. We present a field example showing improved images of hydrate-bearing sediments on seismic data after compensation of attenuation effects. Compressional quality factors estimated from zero-offset Vertical Seismic Profiling data acquired at Mallik, Northwest Territories, Canada, demonstrate significant wave attenuation for hydrate-bearing sediments. These results are in agreement with previous attenuation estimates obtained from sonic logs and crosshole data at different frequency intervals. The application of an inverse Q-filter to compensate attenuation effects of permafrost and hydrate-bearing sediments improved the resolution of surface 3D seismic data and its correlation with log data, particularly for the shallowest gas hydrate interval. Compensation of the attenuation effects of the permafrost likely explains most of the improvements for the shallow gas hydrate zone. Our results show that characterization of the Mallik gas hydrates with seismic data not corrected for attenuation would tend to overestimate thicknesses and lateral extent of hydrate-bearing strata and hence, the volume of hydrates in place. Copyright 2007 by the American Geophysical Union. 2007 English 21699313 10.1029/2007JB004976 Journal of Geophysical Research: Solid Earth 112 Blackwell Publishing Ltd Geological Survey of Canada, 615 Booth Street, Ottawa, ON K1A 0E9, Canada; McGill University, Department of Earth and Planetary Sciences, Montréal, QC H3A 2A7, Canada; Geological Survey of Canada, 3303 - 33 St. N-W, Calgary, AB T2L 2A7, Canada; Geological Survey of Canada, P. O. Box 6000, Sidney, BC V8L 4B2, Canada 10 gas hydrate; permafrost; seismic attenuation; seismic data, Canada; Mackenzie Delta; North America; Northwest Territories https://www.scopus.com/inward/record.uri?eid=2-s2.0-37349004549&doi=10.1029%2f2007JB004976&partnerID=40&md5=c2ec695d8628f53e07777c76c491f835 cited By 37 G. Bellefleur M. Riedel T. Brent F. Wright S.R. Dallimore article Zanoth2007 The leaky mode is a possible attenuation mechanism of seismic waves propagating along lamination in gas-hydrate-bearing sediment layers. This horizontal propagation attenuation mechanism occurs when a high-velocity layer is embedded in a low-velocity zone. This is a typical situation for gas hydrate occurrences. To quantify this attenuation mechanism, a 2D digital rock model based on the crosswell data of the Mallik 2002 Gas Hydrate Production Research Well Program is used. For simplicity, our elastic simulations exclude attenuation mechanisms like scattering loss or intrinsic absorption. We demonstrate that the leaky mode is a significant horizontal attenuation mechanism that cannot be neglected. The effective attenuation of gas-hydrate-bearing sediments is a combination of intrinsic and scattering attenuation by small-scale heterogeneties and the leaky mode. © 2007 Society of Exploration Geophysicists. 2007 English 00168033 10.1190/1.2750375 Geophysics 72 Society of Exploration Geophysicists E159-E163 Freie Universität, Fachbereich Geophysik, Berlin, Germany; ETH Zurich, Geological Institute, Zurich, Switzerland; Spectraseis, Zurich, Switzerland 5 Absorption; Computer simulation; Elastic waves; Mathematical models; Seismic waves; Two dimensional; Wave propagation, Gas-hydrate-bearing sediment; Seismic attenuation, Gas hydrates, absorption; gas hydrate; seismic attenuation; seismic velocity; seismic wave; simulation; wave propagation https://www.scopus.com/inward/record.uri?eid=2-s2.0-34548533646&doi=10.1190%2f1.2750375&partnerID=40&md5=26fa413198f46862b481dc73b1f97500 cited By 7 S.R. Zanoth E.H. Saenger O.S. Krüger S.A. Shapiro article Enkin2007 The J meter coercivity spectrometer is a machine capable of rapid and simple measurement of magnetic hysteresis, isothermal remanence acquisition and magnetic viscosity of rocks and sediments. The J meter was used to study a suite of samples collected from strata in the gas hydrate-bearing JAPEX/JNOC/GSC Mallik 5L-38 well (69.5°N, 134.6°W) in the Mackenzie Delta of the northwestern Canadian Arctic. The Day plot of magnetic hysteresis ratios for these samples is exotic in that the points do not plot along a hyperbola as is usually observed. Rather, they plot as a scatter which is shown to contour into vertical slices using coercivity field (HC) or saturation magnetization (JS), and horizontal slices using the relative quantity of superparamagnetism (JSPM/JS). Optical microscopy reveals that the magnetic minerals are detrital magnetite and authigenic greigite. Greigite is dominant in sands which in situ had &gt;70% gas hydrate saturation and in silts in which gas hydrate growth was blocked by insufficient porosity. We infer that the silts were the accumulation sites for solutes which had been excluded from the pore waters in neighboring coarser-grained sediments during the course of gas hydrate formation. Consequently, we conclude that magnetic properties are related to gas hydrate-related processes, and as such, may have potential as a method of remote sensing for gas hydrate deposits. Copyright 2007 by the American Geophysical Union. 2007 English 21699313 10.1029/2006JB004638 Journal of Geophysical Research: Solid Earth 112 Blackwell Publishing Ltd Geological Survey of Canada-Pacific, PO Box 6000, Sidney, BC V8L 4B2, Canada; Department of Geology, Kazan State University, Kremlyevskaya Str. 18, 420008 Kazan, Russian Federation; Department of Chemistry and Geoscience, Camosun College, 3100 Foul Bay road, Victoria, BC V8P 4J2, Canada 6 chemical alteration; detrital deposit; diagenesis; formation mechanism; gas hydrate; greigite; hysteresis; isotherm; magnetic field; magnetic property; magnetite; porosity; remanent magnetization; viscosity, Canada; Mackenzie Delta; North America; Northwest Territories https://www.scopus.com/inward/record.uri?eid=2-s2.0-34548433885&doi=10.1029%2f2006JB004638&partnerID=40&md5=bbd39c0c9c8a1c2761d755f6aa6ce77d cited By 29 R.J. Enkin J. Baker D. Nourgaliev P. Iassonov T.S. Hamilton article Sun20073115 Heterogeneity of rocks, such as porosity, fractures, and fluids, causes attenuation and velocity dispersion of seismic waves, and induces waveform distortion. This distortion, once detected, offers an insight into the heterogeneous rock properties. In order to detect small velocity dispersion in the exploration seismic frequency band, a new seismic processing method has been developed for uncorrelated vibrator data. This method has been applied to the uncorrelated vibrator VSP data from Mallik gas hydrate research well, MacArthur River uranium mine area, and Outokumpu crystalline rock borehole. Different trends of Q and velocity dispersion have been detected in the above areas, which is a result of the heterogeneities in the rock volume surrounding the boreholes. © 2007 Society of Exploration Geophysicists. 2007 English 9781604238976 10523812 10.1190/1.2793117 SEG Technical Program Expanded Abstracts 26 Society of Exploration Geophysicists 3115-3119 University of Toronto, Toronto, ON, Canada; University of Alberta, Edmonton, AB, Canada 1 Boreholes; Crystalline rocks; Dispersion (waves); Gas hydrates; Petroleum prospecting; Rocks; Seismology; Velocity; Vibrators, Heterogeneous rocks; Seismic frequencies; Seismic processing; Velocity dispersion; Waveform distortions, Seismic prospecting https://www.scopus.com/inward/record.uri?eid=2-s2.0-37549069926&doi=10.1190%2f1.2793117&partnerID=40&md5=7df2d84922fe5caa33f79505ce2661fe cited By 1 L.F. Sun B. Milkereit D. Schmitt article Cordon2006 We perturb the elastic properties and attenuation in the Arctic Mallik methane-hydrate reservoir to produce a set of plausible seismic signatures away from the existing well. These perturbations are driven by the changes we impose on porosity, clay content, hydrate saturation, and geometry. The key is a data-guided, theoretical, rock-physics model that we adopt to link velocity and attenuation to porosity, mineralogy, and amount of hydrate. We find that the seismic amplitude is very sensitive to the hydrate saturation in the host sand and its porosity as well as the porosity of the overburden shale. However, changes to the amount of clay in the sand only weakly alter the amplitude. Attenuation, which may be substantial, must be taken into account during hydrate reservoir characterization because it lowers the amplitude to an extent that may affect the hydrate-volume prediction. The spatial structure of the reservoir affects the seismic reflection: A thinly-layered reservoir produces a noticeably different amplitude than a massive reservoir with the same hydrate volume. © 2006 Society of Exploration Geophysicists. 2006 English 00168033 10.1190/1.2356909 Geophysics 71 Society of Exploration Geophysicists F165-F171 Stanford University, Stanford Rock Physics Laboratory, Geophysics Department, 397 Panama Mall, Stanford, CA 94305, United States 6 Gas hydrates; Mineralogy; Organic compounds; Perturbation techniques; Petroleum reservoirs; Porosity; Reflection, Seismic amplitude; Seismic reflections, Seismology, amplitude; clay; elastic property; porosity; sand; seismic attenuation; seismic reflection; seismic velocity; seismology https://www.scopus.com/inward/record.uri?eid=2-s2.0-33751047705&doi=10.1190%2f1.2356909&partnerID=40&md5=6187bd113d49e95517f197c284b9dda9 cited By 12 I. Cordon J. Dvorkin G. Mavko article Ziatdinov20063240 We apply tube-wave monitoring method to a time-lapse cross-well dataset from Mallik field. Raw waveforms are used for analysis thus avoiding any smearing of 4D response introduced by pre-processing. We perform extensive modeling that includes effects of a source borehole and confirms nature of most prominent arrivals as being tube-wave related. Modeling proves that strongest conversion of tube wave into P and S waves occurs at the sharp acoustic boundary. Data displays clear time-lapse changes in tube-wave related arrivals, while shows no change in first arrivals. Modeling suggests that to explain the data the reservoir changes have to occur at a deeper interval than previously anticipated, below the perforations. Excellent agreement between modeled and experimental data provides us with good confidence in our results. This study represents first application of tube-wave monitoring concept. © 2005 Society of Exploration Geophysicists. 2006 English 9781604236972 10523812 10.1190/1.2370203 SEG Technical Program Expanded Abstracts 25 Society of Exploration Geophysicists 3240-3244 St. Petersburg State University, St. Petersburg, Russian Federation; Shell International Exploration and Production Inc.; Lawrence Berkeley National Laboratory, Berkeley, CA, United States 1 Geophysical prospecting; Shear waves; Tubes (components), Cross-well; Data display; First arrival; P- and S-waves; Pre-processing; Time-lapse response; Tube waves; Wave forms, Acoustics https://www.scopus.com/inward/record.uri?eid=2-s2.0-33845463217&doi=10.1190%2f1.2370203&partnerID=40&md5=8a74c477a4012d871d742f04bbd8a2e4 cited By 0 S. Ziatdinov A. Bakulin B. Kashtan V. Korneev A. Sidorov article Sun20063506 Seismic waves in a porous medium experience attenuation and velocity dispersion. In conventional seismic data processing, velocity dispersion is neglected partially because of insufficient or inconclusive observations. In a medium of high attenuation (Q<30), velocity dispersion is a concern. In order to detect velocity dispersion in the exploration seismic frequency band, uncorrelated Vibroseis data were utilized. We have simulated distortion of the correlation wavelet of Vibroseis data due to velocity dispersion to investigate how dispersion distorts Vibroseis data. Different methods were investigated to develop a robust method to detect and measure velocity dispersion in uncorrelated Vibroseis data. Using the CCMW (cross-correlation with a moving window) method, small velocity variations as a function of frequency were observed in the borehole Vibroseis data from the Mallik gas hydrate research wells (Mackenzie Delta, NWT, Canada). © 2005 Society of Exploration Geophysicists. 2006 English 9781604236972 10523812 10.1190/1.2370264 SEG Technical Program Expanded Abstracts 25 Society of Exploration Geophysicists 3506-3510 University of Toronto, Toronto, ON, Canada 1 Data handling; Gas hydrates; Petroleum prospecting; Porous materials; Seismic prospecting; Seismic waves; Seismology; Velocity, Cross correlations; Function of frequency; Moving window; Robust methods; Seismic data processing; Seismic frequencies; Velocity dispersion; Velocity variations, Dispersion (waves) https://www.scopus.com/inward/record.uri?eid=2-s2.0-33845403051&doi=10.1190%2f1.2370264&partnerID=40&md5=39f504c42301ad948ca264a852fc8e1e cited By 5 L.F. Sun B. Milkereit article Bakulin2006379 We analyze cross-well seismic data from the Mallik experiment and demonstrate time-lapse changes in tube and guided waves. Although such changes are challenging to interpret, they are generally of a larger magnitude compared to any time-lapse signatures of the first P-wave arrivals reported elsewhere. This suggests better sensitivity of tube and guided waves to small production-related changes and their feasibility for reservoir monitoring. © 2005 Society of Exploration Geophysicists. 2006 English 9781604236972 10523812 10.1190/1.2370280 SEG Technical Program Expanded Abstracts 25 Society of Exploration Geophysicists 379-383 Shell International Exploration and Production Inc, United States; Lawrence Berkeley National Laboratory, United States; Nagoya University, Japan; St. Petersburg State University, St. Petersburg, Russian Federation 1 Geophysical prospecting; Seismic waves; Seismology, Cross-well; P-wave arrival; Reservoir monitoring; Seismic datas, Guided electromagnetic wave propagation https://www.scopus.com/inward/record.uri?eid=2-s2.0-33845415179&doi=10.1190%2f1.2370280&partnerID=40&md5=c30cb7bef36066a051200e0fccf15b0d cited By 4 A. Bakulin V. Korneev T. Watanabe S. Ziatdinov article Krüger20061978 This work is inspired by the observation, that gas hydrate bearing sediments have a high velocity in combination with high attenuation. We study numerically the influence of different gas hydrate locations within the pore space on transmitted p-waves. From the wave propagation simulations on the micro-scale it can be seen, that different positions of the gas hydrate in the pore space results in almost the same effective velocities and attenuation, as long as the gas hydrate had contact to the sediment grains. This changes in the case of a suspension, here the attenuation increases and the effective velocity decreases. The resulting p-wave versus gas hydrate saturation plot is in a qualitatively good agreement with experimental results obtained for the Mallik 2L-38 well. © 2005 Society of Exploration Geophysicists. 2006 English 9781604236972 10523812 10.1190/1.2369921 SEG Technical Program Expanded Abstracts 25 Society of Exploration Geophysicists 1978-1982 Freie Universität Berlin, Berlin, Germany 1 Gases; Geophysical prospecting; Hydration; Petroleum prospecting; Seismic waves; Wave propagation, Effective velocity; Gas hydrate bearing sediments; Gas hydrate saturations; High velocity; Micro-scale; Pore space; Sediment grains; Wave propagation simulation, Gas hydrates https://www.scopus.com/inward/record.uri?eid=2-s2.0-33845405489&doi=10.1190%2f1.2369921&partnerID=40&md5=3a960e7b27eedab643519466e4098252 cited By 0 O.S. Krüger E.H. Saenger S.A. Shapiro article Bellefleur2006599 Gas-hydrate accumulations located onshore in Arctic permafrost regions are seen as a potential source of natural gas. Surprisingly, most of the gas hydrate found in the Mackenzie Delta and Beaufort Sea areas was indirectly discovered or inferred from conventional hydrocarbon exploration programs. One of these occurrences, the Mallik gas-hydrate field (Figure 1), has received particular attention over the last 10 years. Two internationally partnered research well programs have intersected three intervals of gas hydrates and have allowed successful extraction of subpermafrost core samples with significant gas hydrates. The gas-hydrate intervals are up to 40 m thick and have high gas-hydrate saturation, sometimes exceeding 80% of pore volume of unconsolidated clastic sediments with average porosities from 25-40%. At Mallik, the gas-hydrate intervals are located at depths of 900-1100 m and are localized on the crest of an anticline. © 2006 Society of Exploration Geophysicists. 2006 English 1070485X 10.1190/1.2202663 Leading Edge 25 Society of Exploration Geophysicists 599-604 Geological Survey of Canada, Ottawa, Canada; Geological Survey of Canada, Pacific, Sidney, B.C., Canada; Geological Survey of Canada, Calgary, Canada 5 Gases; Hydration; Petroleum prospecting, Clastic sediments; Conventional hydrocarbons; Gas hydrate saturations; Hydrate accumulations; Permafrost region; Potential sources; Significant gas; Three interval, Gas hydrates, clastic sediment; gas hydrate; hydrocarbon exploration; natural gas; permafrost; porosity; supermarket, Arctic; Arctic Ocean; Beaufort Sea; Canada; Mackenzie Delta; Northwest Territories https://www.scopus.com/inward/record.uri?eid=2-s2.0-84889901633&doi=10.1190%2f1.2202663&partnerID=40&md5=5ce5a582159ac08e1393ce371b35b818 cited By 39 G. Bellefleur M. Riedel T. Brent article Santos20062986 We analyze the reflectivity properties of the interfaces defined by a contact between a shaly sandstone and the top and bottom of a gas hydrate stability zone (GHSZ), a problem of particular interest in seismic exploration in ocean sediments and continental margins. Our com putations are based on a three phase Biot-type model predicting the existence of three compressional waves and two shear waves. We use some information from the Mallik 5L-38 Gas Hydrate Research Well. The mechanical properties of the gas hydrate bearing rocks are described with appropriate petrophysical models. We present numerical results showing the influence of the gas-hydrate saturation on the amplitude vs. angle curves and the importance of wave energy conversion from fast to slow waves. © 2005 Society of Exploration Geophysicists. 2006 English 9781604236972 10523812 10.1190/1.2370148 SEG Technical Program Expanded Abstracts 25 Society of Exploration Geophysicists 2986-2990 Facultad de Ciencias Astronómicas y Geofísicas, Universidad Nacional de La Plata, CONICET, Paseo del Bosque S/N, 1900-La Plata, Argentina; CONICET, Argentina; Department of Mathematics, Purdue University, W. Lafayette, IN 47907, United States 1 Bearings (machine parts); Energy conversion; Gas hydrates; Gases; Hydration; Petroleum prospecting; Reflection; Seismic prospecting; Shear flow; Shear waves; Wave energy conversion, Compressional waves; Continental margin; Gas hydrate saturations; Gas hydrate stability zones; Numerical results; Ocean sediments; Petrophysical models; Seismic exploration, Phase interfaces https://www.scopus.com/inward/record.uri?eid=2-s2.0-33845425790&doi=10.1190%2f1.2370148&partnerID=40&md5=8806108548e2bffacf26df246f544a86 cited By 0 J.E. Santos J.G. Rubino C.L. Ravazzoli article Zanoth20062304 This paper is concerned with the leaky mode, a possible horizontal attenuation phenomenon of seismic waves in a gas hydrate-bearing sediment layer. This attenuation mechanism in horizontal direction occurs when a high-velocity layer is embedded in a low-velocity zone. This is a typical situation for gas hydrate occurrences. To quantify th is mechanism a digital rock model based on the crosswell-data of the Mallik 2002 Gas Hydrate Research Well Program is created. In our elastic simulations we can exclude attenuation mechanism like scattering loss or intrinsic absorption. We will demonstrate that the leaky mode is a significant horizontal attenuation mechanism which cannot be neglected. © 2005 Society of Exploration Geophysicists. 2006 English 9781604236972 10523812 10.1190/1.2369996 SEG Technical Program Expanded Abstracts 25 Society of Exploration Geophysicists 2304-2308 Fachbereich Geophysik, Freie Universität Berlin, Berlin, Germany 1 Geophysical prospecting; Hydration; Petroleum prospecting; Seismology, Gas hydrate bearing sediments; High velocity; Horizontal attenuation; Intrinsic absorptions; Leaky modes; Low velocity zones; Scattering loss; Seismic attenuation, Gas hydrates https://www.scopus.com/inward/record.uri?eid=2-s2.0-33845406929&doi=10.1190%2f1.2369996&partnerID=40&md5=4135db4bf5b6f117627b3a6e350d3539 cited By 0 S.R. Zanoth E.H. Saenger O.S. Krüger S.A. Shapiro article Chand2006543 The presence of gas hydrate in marine sediments alters their physical properties. In some circumstances, gas hydrate may cement sediment grains together and dramatically increase the seismic P- and S-wave velocities of the composite medium. Hydrate may also form a load-bearing structure within the sediment microstructure, but with different seismic wave attenuation characteristics, changing the attenuation behaviour of the composite. Here we introduce an inversion algorithm based on effective medium modelling to infer hydrate saturations from velocity and attenuation measurements on hydrate-bearing sediments. The velocity increase is modelled as extra binding developed by gas hydrate that strengthens the sediment microstructure. The attenuation increase is modelled through a difference in fluid flow properties caused by different permeabilities in the sediment and hydrate microstructures. We relate velocity and attenuation increases in hydrate-bearing sediments to their hydrate content, using an effective medium inversion algorithm based on the self-consistent approximation (SCA), differential effective medium (DEM) theory, and Biot and squirt flow mechanisms of fluid flow. The inversion algorithm is able to convert observations in compressional and shear wave velocities and attenuations to hydrate saturation in the sediment pore space. We applied our algorithm to a data set from the Mallik 2L-38 well, Mackenzie delta, Canada, and to data from laboratory measurements on gas-rich and water-saturated sand samples. Predictions using our algorithm match the borehole data and water-saturated laboratory data if the proportion of hydrate contributing to the load-bearing structure increases with hydrate saturation. The predictions match the gas-rich laboratory data if that proportion decreases with hydrate saturation. We attribute this difference to differences in hydrate formation mechanisms between the two environments. © 2006 The Authors Journal compilation © 2006 RAS. 2006 English 0956540X 10.1111/j.1365-246X.2006.03038.x Geophysical Journal International 166 Oxford University Press 543-552 Geological Survey of Norway (NGU), Tromsøkontoret, N-9296 Tromsø, Norway; National Oceanography Centre, European Way, Southampton SO14 3ZH, United Kingdom; School of Civil Engineering and Environment, University of Southampton, Highfield, Southampton SO17 1BJ, United Kingdom; US Geological Survey, 384 Woods Hole Road, Woods Hole, MA 02543, United States 2 algorithm; borehole geophysics; elastic wave; gas hydrate; inverse problem; marine sediment; P-wave; S-wave; wave attenuation https://www.scopus.com/inward/record.uri?eid=2-s2.0-33746134734&doi=10.1111%2fj.1365-246X.2006.03038.x&partnerID=40&md5=eaa4dcfa63d8f19c77a33a2c0b052e20 cited By 54 S. Chand T.A. Minshull J.A. Priest A.I. Best C.R.I. Clayton W.F. Waite article Riedel2006 Amplitude and frequency anomalies associated with lakes and drainage systems were observed in a 3D seismic data set acquired in the Mallik area, Mackenzie Delta, Northwest Territories, Canada. The site is characterized by large gas hydrate deposits inferred from well-log analyses and coring. Regional interpretation of the gas hydrate occurrences is mainly based on seismic amplitude anomalies, such as brightening or blanking of seismic energy. Thus, the scope of this research is to understand the nature of the amplitude behavior in the seismic data. We have therefore analyzed the 3D seismic data to define areas with amplitude reduction due to contamination from lakes and channels and to distinguish them from areas where amplitude blanking may be a geologic signal. We have used the spectral ratio method to define attenuation (Q) over different areas in the 3D volume and subsequently applied Q-compensation to attenuate lateral variations ofdispersive absorption. Underneath larger lakes, seismic amplitude is reduced and the frequency content is reduced to 20-40 Hz, which is half the original bandwidth. Traces with source-receiver pairs located inside of lakes show an attenuation factor Q of ∼ 40, approximately half of that obtained for source-receiver pairs situated on deep, continuous permafrost outside of lakes. Deeper reflections occasionally identified underneath lakes show low-velocity-related pull-down. The vertical extent of the washout zones is enhanced by acquisition with limited offsets and from processing parameters such as harsh mute functions to reduce noise from surface waves. The strong attenuation and seismic pull-down may indicate the presence of unfrozen water in deeper lakes and unfrozen pore water within the sediments underlying the lakes. Thus, the blanking underneath lakes is not necessarily related to gas migration or other in situ changes in physical properties potentially associated with the presence of gas hydrate. © 2006 Society of Exploration Geophysicists. 2006 English 00168033 10.1190/1.2338332 Geophysics 71 Society of Exploration Geophysicists B183-B191 Natural Resources Canada, Geological Survey of Canada - Sidney Pacific Geoscience Center, 9860 West Saanich Road, Sidney, BC V8L 4B2, Canada; Natural Resources Canada, Geological Survey of Canada - Ottawa, 615 Booth Street, Ottawa, ON K1A 0E9, Canada 6 Drainage; Lakes; Permafrost; Seismic waves; Spectrum analysis; Surface waves; Well logging, Gas hydrate deposits; Seismic amplitude; Seismic data, Seismology, amplitude; data interpretation; seismic attenuation; seismic data; seismic migration; seismology; spectral analysis; surface wave; three-dimensional modeling; well logging, Canada; Mackenzie Delta; North America; Northwest Territories https://www.scopus.com/inward/record.uri?eid=2-s2.0-33751070379&doi=10.1190%2f1.2338332&partnerID=40&md5=43b4df8bfd7f327a71cd2101208d0373 cited By 21 M. Riedel G. Bellefleur S.R. Dallimore A. Taylor J.F. Wright article Haberer2006519 The aromatic hydrocarbon biomarker distributions of thirty Oligocene sediment samples with different lithology (lignite, clay and sand) from the JAPEX/JNOC/GSC et al. Mallik 5L-38 Gas Hydrate Production Research Well, Canada, were analyzed using gas chromatography-mass spectrometry (GC-MS). The compositions vary with lithology, indicating a change in palaeoenvironmental conditions at the time of deposition. Aromatic diterpenoids of the abietane type are more abundant in the lignite samples than in the clay samples and represent a gymnosperm (e.g., conifer) dominated palaeovegetation. In contrast, in the clay samples aromatic triterpenoids are generally preserved as major constituents, indicating angiosperm dominated vegetation. The sand samples contain only minor amounts of aromatic terpenoids, but show a preference for diterpenoid gymnosperm markers. To recognise gymnosperm versus angiosperm dominated palaeoenvironments a new ratio, termed the angiosperm-gymnosperm aromatic ratio (AGAR), has been developed. Thus, the terpenoid distribution in the deltaic sediments provides information on the compositional changes in the plant community at the Mallik site (lignites) and the hinterland (clays) over time. Concomitantly, the changing dominance in the plant communities allows an insight into varying climatic conditions during the late Oligocene in the area. Additionally, the aromatic biomarker composition has been used to assess the level of thermal maturity of the organic matter in the Mallik samples and indicates a prevailing immature character. © 2006 Elsevier Ltd. All rights reserved. 2006 English 01466380 10.1016/j.orggeochem.2006.01.004 Organic Geochemistry 37 519-538 GeoForschungsZentrum (GFZ) Potsdam, Telegrafenberg, D-14473 Potsdam, Germany 5 Angiosperm-gymnosperm aromatic ratio (AGAR); Aromatic diterpenoids; Climatic conditions; Gymnosperm markers, Aromatic hydrocarbons; Composition; Environmental impact; Gas chromatography; Hydration; Mass spectrometry; Sediments, Biomarkers, aromatic hydrocarbon; biomarker; geochemistry; Oligocene; paleoenvironment; sediment; vegetation, Canada; North America, Coniferophyta; Gymnospermae; Magnoliophyta https://www.scopus.com/inward/record.uri?eid=2-s2.0-33646467368&doi=10.1016%2fj.orggeochem.2006.01.004&partnerID=40&md5=d583b2b30952fca4aad2fc7f2128f543 cited By 61 R.M. Haberer K. Mangelsdorf H. Wilkes B. Horsfield article Uchida200593 The Mallik 5L-38 gas hydrate production research well was drilled to 1166 m early in 2002, and abundant gas-hydrate-bearing cores were successfully retrieved from a variety of sediments. Gas hydrate-dominant layers were identified at depths of 889 to 1108 m. Gas-hydrate-bearing strata typically range from 10 cm to a few meters in thickness, and gas hydrate saturations in most gas hydrate layers were quite high. Pore-space hydrate is very small in size and fills the intergranular porosity of sandy sediments. The X-ray CT images of gas-hydrate-bearing sediments always show very uniform CT values. Those values in some parts of the sediment samples suggest that the methane hydrate contents range from 23 to 36 vol.% of the sample, which indicate high methane hydrate saturations in the intergranular porosity of the sand samples. Most of the gas hydrates fill the intergranular pore systems of sands, which are derived from channels and crevasse splay/levee deposits. Gas hydrate is less frequently found in siltstones and mudstones from interdistributary bay and overbank deposits. Measurements of water permeability were undertaken, initially keeping the hydrate stable at 10 °C by pressurizing, and then depressurizing gradually. Initial water permeabilities of gas hydrate/ice filled sands range from 1 to 5 millidarcy. Pore-space hydrate was observed to occur primarily in fine- to medium-grained arenite sands. X-ray diffraction and Raman spectroscopy measurements showed that pore-space hydrates contained in sands are mainly Structure I. P-wave velocities of those sands, measured over the interval -20 to 5 °C, decrease from 4 to 3 km/sec as water ice melted, S-wave velocities decrease from about 2.5 km/sec at -20 °C to about 1.5 km/sec at 5°C. Measurements of mechanical strength and electrical resistivity were also undertaken. 2005 English 09168753 Nihon Enerugi Gakkaishi/Journal of the Japan Institute of Energy 84 93-98 JAPEX Research Center, 1-2-1 Hamada, Mihama, Chiba 261-0025, Japan 2 Computerized tomography; Deposits; Electric resistance; Gas hydrates; Geology; Grain size and shape; Natural gas well drilling; Porosity; Raman spectroscopy; Sediments; Strength of materials; X ray diffraction, Mallik, Canada; Methane hydrate; P- & S-wave velocity; Pore-space hydrates, Natural gas https://www.scopus.com/inward/record.uri?eid=2-s2.0-19944395525&partnerID=40&md5=50fbd5dc72f1811d2ac8ccbbe8216496 cited By 0 T. Uchida article Yasuda200588 It is estimated that significant amount of methane hydrate resources are deposited offshore Japan and the Research Consortium of Methane Hydrate Resources in Japan (MH21 Research Consortium) was established to undertake the "Japan's Methane Hydrate Exploitation Program" which was prepared by the Ministry of Economy, Trade and Industry and announced in 2001. MH21 Research Consortium planned onshore tests of gas production from gas hydrate reservoir and the Mallik 2002 Gas Hydrate Production Research Well Program was formed in which eight bodies participated from five countries. The test site was located in onshore Mackenzie delta of Northwestern Canada. The swamp feature of the site restricted the whole test operation only in winter when frozen firm ground and transportation road are formed. From December 25th 2001 to March 14th 2002, one gas production test well and two observation wells were drilled. Pressure draw down test using MDT and a hot water circulation test were tried , and the latter test yielded 468m3 dissociated gas from the hydrate reservoir, which was the first success of gas production from naturally deposited gas hydrate reservoir. In December 2003, Mallik International Symposium was held in Chiba, Japan with more than 200 researchers' participation from thirteen countries. The success of the Mallik Program was officially announced for the first time at the Symposium. 2005 Japanese 09168753 Nihon Enerugi Gakkaishi/Journal of the Japan Institute of Energy 84 88-92 Japan Oil, Gas and Metals National Corporation, 1-2-2 Hamada, Mihama, Chiba 261-0025, Japan 2 Economics; Methane; Motor transportation; Natural gas; Natural gas well drilling; Technical presentations, Gas hydrate reservoir; Gas production; Mallik; MH21, Gas hydrates https://www.scopus.com/inward/record.uri?eid=2-s2.0-19944404248&partnerID=40&md5=fa296da8ab63a1e0dee20e185b950d8f cited By 0 M. Yasuda article Dallimore2005 2005 English 00687626 10.4095/220702 Bulletin of the Geological Survey of Canada Energy, Mines and Resources Canada iii-iv Geological Survey of Canada - Pacific, 9860 West Saanich Road, Sidney, BC V8L 4B2, Canada; United States Geological Survey, Denver Federal Centre, Box 25046, Denver, CO 80225, United States; JAPEX Research Center, 1-2-1 Hamada, Mihama-ku, Chiba 2610025, Japan; GeoForschungsZentrum, Telegrafenberg D-14473 Potsdam, Germany; United States Department of Energy, National Energy Technology Laboratory, 3610 Collins Ferry Road, Morgantown, WV 26507, United States; BP Canada Energy Company, Calgary 240-4th Avenue SW, Calgary, Alta. T2P 2H8, Canada; JNOC Technology Research Center, Japan National Oil Corporation, 1-2-2 Hamada, Mihama-ku, Chiba 261-0025, Japan 585 gas hydrate https://www.scopus.com/inward/record.uri?eid=2-s2.0-27744500622&partnerID=40&md5=c4f4b022aabc3644a4d64f3b3521b91b cited By 131 S.R. Dallimore T.S. Collet A.E. Taylor T. Uchida M. Weber A. Chandra T.H. Mroz E.M. Caddel T. Inoue article Inoue2005106 This paper presents an overview of the pressure drawdown test and the thermal stimulation test at the Mallik 2002 gas hydrate research well, conducted in February and March 2002. Pressure drawdown tests were conducted on methane hydrate, free gas, and water intervals, using Schlumberger's Modular Formation Dynamics Tester (MDT) wireline tool. The thermal stimulation test was designed to increase the in-situ temperature of a well-defined and constrained methane hydrate reservoir above the methane hydrate stability point, while maintaining constant pressure. The objectives of the production tests were to confirm the feasibility of production of natural gas from methane hydrate deposits by depressurization and thermal stimulation, and to collect sufficient data to determine relevant methane hydrate formation properties. The production tests were successful in that significant amounts of the in-situ dissociation properties, as well as other scientific measurements, were obtained. 2005 English 09168753 Nihon Enerugi Gakkaishi/Journal of the Japan Institute of Energy 84 106-111 Japan Oil, Gas and Metals National Corporation, 1-2-2 Hamada, Mihama-ku, Chiba 261-0025, Japan 2 Methane; Natural gas; Natural gas well drilling; Production, Mallik, Canada; MDT; Methane hydrates; Pressure drawdown tests; Production tests; Thermal stimulation tests, Gas hydrates https://www.scopus.com/inward/record.uri?eid=2-s2.0-19944402198&partnerID=40&md5=3812fe5dfa90f5264d37b3d7a951e3d1 cited By 2 T. Inoue article Lu20051 Gas hydrate samples recovered from a cold vent field offshore Vancouver Island were studied in detail both by macroscopic observations and instrumental methods (powder X-ray diffraction method (PXRD), nuclear magnetic resonance (NMR), and Raman spectroscopy). It was found that gas hydrates were massive from 2.64 to 2.94 m below seafloor (mbsf), elongated, nodular and tabular from 4.60 to 4.81 mbsf, and vein-like from 5.48 to 5.68 mbsf, showing a trend of decreasing hydrate content with increasing depth. All samples were determined to be structure I hydrate from PXRD, NMR, and Raman spectroscopies. The hydration numbers were estimated to be 6.1 ± 0.2 on average as determined from the methane distribution over the cage sites from NMR and Raman analytical results. Estimates of conversion levels indicated that ∼78% of the water in the massive samples was hydrate, down to a low value of ∼0.4% for the pore hydrate samples. The results are compared with measurements on synthetic hydrates and samples recovered from below the permafrost on the Mallik site. Differences in methane content and lattice parameters for synthetic and natural samples are relatively minor. Additional work is needed to address the presence of minor gas components and the heterogeneity of natural hydrate samples. Copyright 2005 by the American Geophysical Union. 2005 English 21699313 10.1029/2005JB003900 Journal of Geophysical Research: Solid Earth 110 Blackwell Publishing Ltd 1-9 Steacie Institute for Molecular Sciences, National Research Council of Canada, 100 Sussex Drive, Ottawa, Ont. K1A 0R6, Canada; Pacific Geoscience Center, Geological Survey of Canada, P.O. Box 6000, Sidney, BC V8L 4B2, Canada; School of Earth and Ocean Sciences, University of Victoria, Victoria, BC V8W 2Y2, Canada 10 cold seep; gas hydrate, British Columbia; Canada; North America; Vancouver Island https://www.scopus.com/inward/record.uri?eid=2-s2.0-29444439032&doi=10.1029%2f2005JB003900&partnerID=40&md5=2c4e6cc3a8fd4eb2426f56c3fbebe327 cited By 59 H. Lu I. Moudrakovski M. Riedel G. Spence R. Dutrisac J. Ripmeester F. Wright S. Dallimore article Kurihara2005112 The results of the thermal production test and Modular Formation Dynamics Tester (MDT) tests conducted at the Mallik 5L-38 gas hydrate production research well were analyzed, using the numerical simulator coded for gas hydrate reservoirs. The reservoir models were constructed as a series of grid blocks. In the simulation for the thermal production test, the reservoir model was tuned through history matching, by introducing the concept that part of the circulating hot water might have invaded into the reservoir, which resulted in the excellent agreement between observed and simulated performances. Using the history-matched reservoir model, sensitivity simulation and prediction of future performances were conducted to examine the effects of uncertain reservoir parameters and the gas hydrate dissociation/production methods on the recovery of gas from the Mallik reservoir. In the MDT test simulation, to investigate the applicability of conventional pressure transient test analysis methods, bottomhole pressure responses during MDT tests in hypothetical and actual gas hydrate zones were simulated and were then analyzed by the conventional analysis methods. This study revealed that conventional methods might indicate the average effective permeability over the area of gas hydrate dissociation while the estimation of the radius of gas hydrate dissociation was quite imprecise. 2005 English 09168753 Nihon Enerugi Gakkaishi/Journal of the Japan Institute of Energy 84 112-118 Japan Oil Engineering Company Limited, 1-7-3 Kachidoki, Chuo-ku, Tokyo 104-0054, Japan 2 Computer simulation; Mathematical models; Natural gas well drilling; Sensitivity analysis, History matching; Methane hydrates; Modular formation dynamics tester (MDT); Thermal methods; Well tests, Gas hydrates https://www.scopus.com/inward/record.uri?eid=2-s2.0-19944410511&partnerID=40&md5=21029701e5fdad7a37d1965e9dc6fcef cited By 0 M. Kurihara article Guerin2005 Recent sonic and seismic data in gas hydrate-bearing sediments have indicated strong waveform attenuation associated with a velocity increase, in apparent contradiction with conventional wave propagation theory. Understanding the reasons for such energy dissipation could help constrain the distribution and the amounts of gas hydrate worldwide from the identification of low amplitudes in seismic surveys. A review of existing models for wave propagation in frozen porous media, all based on Biot's theory, shows that previous formulations fail to predict any significant attenuation with increasing hydrate content. By adding physically based components to these models, such as cementation by elastic shear coupling, friction between the solid phases, and squirt flow, we are able to predict an attenuation increase associated with gas hydrate formation. The results of the model agree well with the sonic logging data recorded in the Mallik 5L-38 Gas Hydrate Research Well. Cementation between gas hydrate and the sediment grains is responsible for the increase in shear velocity. The primary mode of energy dissipation is found to be friction between gas hydrate and the sediment matrix, combined with an absence of inertial coupling between gas hydrate and the pore fluid. These results predict similar attenuation increase in hydrate-bearing formations over most of the sonic and seismic frequency range. Copyright 2005 by the American Geophysical Union. 2005 English 15252027 10.1029/2005GC000918 Geochemistry, Geophysics, Geosystems 6 Borehole Research Group, Lamont-Doherty Earth Observatory, Route 9W, Palisades, NY 10964, United States 7 https://www.scopus.com/inward/record.uri?eid=2-s2.0-33646721772&doi=10.1029%2f2005GC000918&partnerID=40&md5=acb2770a38cf857f73da63ae9f1afe3e cited By 69 G. Guerin D. Goldberg article Henninges20051 Detailed knowledge about thermal properties of rocks containing gas hydrate is required in order to quantify processes involving gas hydrate formation and decomposition in nature. In the framework of the Mallik 2002 program, three wells penetrating a continental gas hydrate occurrence under permafrost were successfully equipped with permanent fiber-optic distributed temperature sensing cables. Temperature data were collected over a 21-month period after completing the wells. Thermal conductivity profiles were calculated from the geothermal data as well as from a petrophysical model derived from the available logging data and application of mixing law models. Results indicate that thermal conductivity variations are mainly lithologically controlled with a minor influence from hydrate saturation. Average thermal conductivity values of the hydrate-bearing sediments range between 2.35 and 2.77 W m-1 K-1. Maximum gas hydrate saturations can reach up to about 90% at an average porosity of 0.3. Copyright 2005 by the American Geophysical Union. 2005 English 21699313 10.1029/2005JB003734 Journal of Geophysical Research: Solid Earth 110 Blackwell Publishing Ltd 1-11 Section Geothermics, GeoForschungsZentrum Potsdam, D-14473 Potsdam, Germany; Fachgebiet Angewandte Geophysik, Technische Universität Berlin, Ackerstraße 71-76, D-13355 Berlin, Germany 11 gas hydrate; sediment property; thermal conductivity https://www.scopus.com/inward/record.uri?eid=2-s2.0-30144437414&doi=10.1029%2f2005JB003734&partnerID=40&md5=099dd97352bd4c0a3cd0feeb767eee58 cited By 77 J. Henninges E. Huenges H. Burkhardt article Takahashi200599 At Mallik of the Mackenzie Delta in the Arctic Canada, over a 79 day period, from December 25, 2001 to March 14, 2002, three (3) wells were drilled through the hydrate formation beneath permafrost on a line at 40m distance, where coring, logging, various science experiments and production testing were performed. This research project was organized and funded by participants from five (5) countries of Japan, Canada, US, Germany and India. Japan National Oil Corporation (JNOC) and Japan Petroleum Exploration Co. Ltd. (JAPEX) undertook its operation while the Geological Survey of Canada (GSC) coordinated the science program. This paper describes the drilling operation including its logistics of the Mallik 2002 Gas Hydrate Production Research Well Program. 2005 Japanese 09168753 Nihon Enerugi Gakkaishi/Journal of the Japan Institute of Energy 84 99-105 Japan Petroleum Exploration Co., Ltd., 2-2-20 Higashi-shinagawa, Shinagawa, Tokyo 140-0002, Japan 2 Crude petroleum; Logistics; Natural gas well drilling; Project management; Societies and institutions, Arctic operations; Geological Survey of Canada (GSC); Japan National Oil Corporation (JNOC); Remote operations, Gas hydrates https://www.scopus.com/inward/record.uri?eid=2-s2.0-19944363184&partnerID=40&md5=b40434c0f86f87472bd44f2992d87bf7 cited By 0 H. Takahashi article Sun20051 In-situ dielectric properties of natural gas hydrate are measured for the first time in the Mallik 5L-38 Well in the Mackenzie Delta, Canada. The average dielectric constant of the hydrate zones is 9, ranging from 5 to 20. The average resistivity is >5 ohm.m in the hydrate zones, ranging from 2 to 10 ohm.m at a 1.1 GHz dielectric tool frequency. The dielectric logs show similar trends with sonic and induction resistivity logs, but exhibits inherently higher vertical resolution (<5 cm). The average in-situ hydrate saturation in the well is about 70%, ranging from 20% to 95%. The dielectric estimates are overall in agreement with induction estimates but the induction log tends to overestimate hydrate content up to 15%. Dielectric estimates could be used as a better proxy of in-situ hydrate saturation in modeling hydrate dynamics. The fine-scale structure in hydrate zones could help reveal hydrate formation history. Copyright 2005 by the American Geophysical Union. 2005 English 00948276 10.1029/2004GL021976 Geophysical Research Letters 32 1-4 Lamont-Doherty Earth Observatory, Columbia University, Palisades, NY 10964, United States 4 Dielectric properties; Electric conductivity; Frequencies; Mathematical models; Natural gas; Dielectric properties; Dielectric properties of gases; Electric logging; Hydration; Induction logging, Dielectric tools; Hydrate saturation; Hydrate zones; Induction logs, Gas hydrates; Gas hydrates, clathrate; dielectric property; gas hydrate, Dielectric methods; Dielectric tools; Fine-scale structures; High resolution; Hydrate formation; Resistivity logs; Situ hydrates; Vertical resolution https://www.scopus.com/inward/record.uri?eid=2-s2.0-19744378644&doi=10.1029%2f2004GL021976&partnerID=40&md5=c82854177ff720bae6d7f50642cfcb45 cited By 20 Y.F. Sun D. Goldberg article haberer2005characterization 2005 10.4095/220702 Scientifique Results from Mallik 2002 Gas Hydrate Production Research Well Program, Mackenzie Delta, Northwest Territories, Canada Geological Survey of Canada, Bulletin 585 Geological Survey of Canada RM Haberer Kai Mangelsdorf V Dieckmann A Fuhrmann Heinz Wilkes Brian Horsfield article Boswell20058 The potential of offshore deposits of methane hydrates as energy resource is discussed. The efforts to develop methods that would make production of methane from hydrate both technologically feasible and economically viable are also presented. Methane hydrate is a very efficient storehouse of energy, and when dissociated, a single cubic foot of solid hydrate releases as much as 180 cubic feet of methane gas. work at the Mallik site in the Canadian Arctic has established that production of methane from hydrates is technologically feasible. The US national methane hydrate research program is now performing field and laboratory studies designed to accelerate the commercially viable production of methane from hydrate in Alaska. 2005 English 00256501 Mechanical Engineering 127 8-11 U.S. Department of Energy, Natl. Energy Technology Laboratory, Morgantown, WV, United States SUPPL. Heat flow; Methane hydrates; Seismic reflection; Well logs, Computer simulation; Computerized tomography; Diffusion; Dissociation; Hydrates; Mechanical permeability; Natural gas; Nuclear magnetic resonance spectroscopy; Offshore petroleum prospecting; Raman spectroscopy; Sediments; Seismic prospecting, Methane https://www.scopus.com/inward/record.uri?eid=2-s2.0-14644433605&partnerID=40&md5=f9050a60c1916b7a4ceb308d6248c290 cited By 1 R. Boswell article Moridis2004219 The Mallik site represents an onshore permafrost-associated gas hydrate accumulation in the Mackenzie Delta, Northwest Territories, Canada. A gas hydrate research well was drilled at the site in 1998. The objective of this study is the analysis of various gas production scenarios from five methane hydrate-bearing zones at the Mallik site. In Zone #1, numerical simulations using the EOSHYDR2 model indicated that gas production from hydrates at the Mallik site was possible by depressurizing a thin free gas zone at the base of the hydrate stability field. Horizontal wells appeared to have a slight advantage over vertical wells, while multiwell systems involving a combination of depressurization and thermal stimulation offered superior performance, especially when a hot noncondensible gas was injected. Zone #2, which involved a gas hydrate layer with an underlying aquifer, could yield significant amounts of gas originating entirely from gas hydrates, the volumes of which increased with the production rate. However, large amounts of water were also produced. Zones #3, #4 and #5 were lithologically isolated gas hydrate-bearing deposits with no underlying zones of mobile gas or water. In these zones, thermal stimulation by circulating hot water in the well was used to induce dissociation. Sensitivity studies indicated that the methane release from the hydrate accumulations increased with the gas hydrate saturation, the initial formation temperature, the temperature of the circulating water in the well, and the formation thermal conductivity. Methane production appears to be less sensitive to the specific heat of the rock and of the hydrate, and to the permeability of the formation. © 2004 Published by Elsevier B.V. 2004 English 09204105 10.1016/j.petrol.2004.02.015 Journal of Petroleum Science and Engineering 43 219-238 Earth Sciences Division, Lawrence Berkeley Natl. Laboratory, University of California, 1 Cyclotron Road, Berkeley, CA 94720, United States; United States Geological Survey, Denver, CO 80225-0046, United States; Geological Survey of Canada, Sidney, BC V8L 4B2, Canada; Japan National Oil Corporation, Chiba 261-0025, Japan; Adams Pearson Associates Inc., Calgary, Alta. T2P 3T6, Canada 3-4 Depressurization; Thermal stimulations, Computer simulation; Hydrates; Lithology; Methane; Specific heat; Thermal conductivity; Thermal effects, Gas fuel manufacture, gas hydrate; gas production; numerical model; permafrost, Canada; Mackenzie Delta; North America; Northwest Territories https://www.scopus.com/inward/record.uri?eid=2-s2.0-3442901975&doi=10.1016%2fj.petrol.2004.02.015&partnerID=40&md5=da3e821165d71b26f88b4f2448fbff05 cited By 204 G.J. Moridis T.S. Collett S.R. Dallimore T. Satoh S. Hancock B. Weatherill article Chand2004 Observations of velocities in sediments containing gas hydrates show that the strength of sediments increases with hydrate saturation. Hence it is expected that the attenuation of these sediments will decrease with increasing hydrate saturation. However, sonic log measurements in the Mallik 2L-38 well and cross hole tomography measurements in the Mallik field have shown that attenuation increases with hydrate saturation. We studied a range of mechanisms by which increasing hydrate saturation could cause increased attenuation. We found that a difference in permeability between the host sediment and the newly formed hydrate can produce the observed effect. We modelled attenuation in terms of Biot and squirt flow mechanisms in composite media. We have used our model to predict observed attenuations in the Mallik 2L-38 well, Mackenzie Delta, Canada. Copyright 2004 by the American Geophysical Union. 2004 English 00948276 10.1029/2004GL020292 Geophysical Research Letters 31 L14609 1-4 School of Ocean and Earth Science, Southampton Oceanography Centre, European Way, Southampton SO14 3ZH, United Kingdom 14 Attenuation; Gas hydrates; Mechanical permeability; Sediments, Seismic attenuation; Squirt flow mechanism, Seismic waves, borehole geophysics; gas hydrate; permeability; seismic attenuation; seismic wave, Canada; Mackenzie Delta; North America; Northwest Territories https://www.scopus.com/inward/record.uri?eid=2-s2.0-4644323579&doi=10.1029%2f2004GL020292&partnerID=40&md5=7700212f10782935fe7fa15a8290dc90 cited By 51 S. Chand T.A. Minshull article Winters20041221 This paper presents results of shear strength and acoustic velocity (p-wave) measurements performed on: (1) samples containing natural gas hydrate from the Mallik 2L-38 well, Mackenzie Delta, Northwest Territories; (2) reconstituted Ottawa sand samples containing methane gas hydrate formed in the laboratory; and (3) ice-bearing sands. These measurements show that hydrate increases shear strength and p-wave velocity in natural and reconstituted samples. The proportion of this increase depends on (1) the amount and distribution of hydrate present, (2) differences, in sediment properties, and (3) differences in test conditions. Stress-strain curves from the Mallik samples suggest that natural gas hydrate does not cement sediment grains. However, stress-strain curves from the Ottawa sand (containing laboratory-formed gas hydrate) do imply cementation is present. Acoustically, rock physics modeling shows that gas hydrate does not cement grains of natural Mackenzie Delta sediment. Natural gas hydrates are best modeled as part of the sediment frame. This finding is in contrast with direct observations and results of Ottawa sand containing laboratory-formed hydrate, which was found to cement grains (Waite et al. 2004). It therefore appears that the microscopic distribution of gas hydrates in sediment, and hence the effect of gas hydrate on sediment physical properties, differs between natural deposits and laboratory-formed samples. This difference may possibly be caused by the location of water molecules that are available to form hydrate. Models that use laboratory-derived properties to predict behavior of natural gas hydrate must account for these differences. 2004 English 0003004X 10.2138/am-2004-8-909 American Mineralogist 89 Mineralogical Society of America 1221-1227 U.S. Geological Survey, 384 Woods Hole Road, Woods Hole, MA 02543, United States; Inst. of Geological/Nuclear Science, 69 Gracefield Road, Lower Hutt, New Zealand 8-9 Acoustic wave velocity; Cements; Gases; Hydration; Laboratories; Methane; Molecules; Natural gas; Natural gas wells; Physical properties; Sand; Sediments; Seismic waves; Shear flow; Stress-strain curves; Wave propagation, Derived properties; Direct observations; Methane gas hydrates; Microscopic distribution; P-wave velocity; Reconstituted sample; Rock physics model; Sediment properties, Gas hydrates, acoustic property; clathrate; gas hydrate; methane; sediment property; shear strength; water content https://www.scopus.com/inward/record.uri?eid=2-s2.0-4444244874&doi=10.2138%2fam-2004-8-909&partnerID=40&md5=b05feae13d230988a79be90127c3b35c cited By 204 W.J. Winters I.A. Pecher W.F. Waite D.H. Mason article Takahashi200453 The first production test of methanehydrate layers was carried out in the Mackenzie Delta in the Canadian Arctic. Three wells were drilled through hydrate layers at a depth of approximately 900 to 1100 m beneath 640 m of permafrost on a line at 40-m spacing. Coring, logging, and other scientific experiments and production test were performed over a 79-day period. The Geologic Survey of Canada (GSC) was coordinator of the science program, and Japan Natl. Oil Corp. (JNOC) and Japan Petroleum Exploration Co. (JAPEX) were operators. 2004 English 01492136 JPT, Journal of Petroleum Technology 56 53-54 Japan Petroleum Exploration Co. Ltd., Japan; Japan Natl. Oil Corp., Japan; Canadian Petroleum Engineering Inc., Canada 4 Coring; Gas hydrate production; Hole enlargement; Openhole well logs, Core samples; Methane; Natural gas well drilling; Natural gas well logging; Natural gas well production; Permafrost, Gas hydrates https://www.scopus.com/inward/record.uri?eid=2-s2.0-1842832851&partnerID=40&md5=999c45123e42c6a26c983a4aa2ce21d4 cited By 4 H. Takahashi T. Yonezawa E. Fercho article Chand2004573 The presence of gas hydrate in oceanic sediments is mostly identified by bottom-simulating reflectors (BSRs), reflection events with reversed polarity following the trend of the seafloor. Attempts to quantify the amount of gas hydrate present in oceanic sediments have been based mainly on the presence or absence of a BSR and its relative amplitude. Recent studies have shown that a BSR is not a necessary criterion for the presence of gas hydrates, but rather its presence depends on the type of sediments and the in situ conditions. The influence of hydrate on the physical properties of sediments overlying the BSR is determined by the elastic properties of their constituents and on sediment microstructure. In this context several approaches have been developed to predict the physical properties of sediments, and thereby quantify the amount of gas/gas hydrate present from observed deviations of these properties from those predicted for sediments without gas hydrate. We tested four models: the empirical weighted equation (WE); the three-phase effective-medium theory (TPEM); the three-phase Biot theory (TPB) and the differential effective-medium theory (DEM). We compared these models for a range of variables (porosity and clay content) using standard values for physical parameters. The comparison shows that all the models predict sediment properties comparable to field values except for the WE model at lower porosities and the TPB model at higher porosities. The models differ in the variation of velocity with porosity and clay content. The variation of velocity with hydrate saturation is also different, although the range is similar. We have used these models to predict velocities for field data sets from sediment sections with and without gas hydrates. The first is from the Mallik 2L-38 well, Mackenzie Delta, Canada, and the second is from Ocean Drilling Program (ODP) Leg 164 on Blake Ridge. Both data sets have Vp and Vs information along with the composition and porosity of the matrix. Models are considered successful if predictions from both Vp and Vs match hydrate saturations inferred from other data. Three of the models predict consistent hydrate saturations of 60-80 per cent from both Vp and Vs from log and vertical seismic profiling data for the Mallik 2L-38 well data set, but the TPEM model predicts 20 per cent higher saturations, as does the DEM model with a clay-water starting medium. For the clay-rich sediments of Blake Ridge, the DEM, TPEM and WE models predict 10-20 per cent hydrate saturation from Vp data, comparable to that inferred from resistivity data. The hydrate saturation predicted by the TPB model from Vp is higher. Using Vs data, the DEM and TPEM models predict very low or zero hydrate saturation while the TPB and WE models predict hydrate saturation very much higher than those predicted from Vp data. Low hydrate saturations are observed to have little effect on Vs. The hydrate phase appears to be connected within the sediment microstructure even at low saturations. © 2004 RAS. 2004 English 0956540X 10.1111/j.1365-246X.2004.02387.x Geophysical Journal International 159 573-590 School of Ocean and Earth Science, Southampton Oceanography Centre, European Way, Southampton SO14 3ZH, United Kingdom; Inst. Nazl. Oceanogr. Geofis. Sper., Borgo Grotta Gigante 42c, 34010 Sgonico, Trieste, Italy 2 comparative study; hydration; marine sediment; numerical model; P-wave; S-wave; saturation; seismic reflection; seismic survey; seismic velocity https://www.scopus.com/inward/record.uri?eid=2-s2.0-4644228964&doi=10.1111%2fj.1365-246X.2004.02387.x&partnerID=40&md5=f3cd7fba7a2b0880b803c900d1eca233 cited By 163 S. Chand T.A. Minshull D. Gei J.M. Carcione article Moridis2004175 The Mallik site represents an onshore permafrost-associated methane hydrate accumulation in the Mackenzie Delta, Northwest Territories, Canada. This study focuses on gas production at the Mallik site from hydrate deposits that are underlain by either a freewater zone (Class 2) or an impermeable boundary (Class 3). The production analysis was conducted with a numerical simulator that can model the nonisothermal CH4 release, phase behavior, and flow under conditions typical of CH4-hydrate deposits by solving the coupled equations of mass and heat balance. Accumulations with a CH4-hydrate saturation of at least 50% were studied. Dissociation was induced mainly by a combination of thermal stimulation and depressurization as hot fluids circulated between injection and production wells. The effects of salinity and of pressure changes at the wells were also accounted for. The production strategy resulted in a zero net water production. The simulation results indicated that the amount of CH4 released from the dissociating hydrate deposits is sensitive to the hydrate saturation, the initial temperature, the specific enthalpy, and the flow rate of the circulating fluids. © 2004 Society of Petroleum Engineers. 2004 English 10946470 10.2118/88039-PA SPE Reservoir Evaluation and Engineering 7 Society of Petroleum Engineers 175-183 Hydrology/Reservoir Dynamics Dept., Earth Sciences Division, Lawrence Berkeley Natl. Laboratory, Berkeley, CA, United States 3 Computer simulation; Enthalpy; Fluid dynamics; Hydrates; Methane; Pressurization; Saturation (materials composition); Thermal effects, Freewater zone; Gas production; Production wells; Water production, Gas fuel analysis, gas hydrate; hydrocarbon reserve; hydrocarbon technology; methane; numerical model; permafrost, Canada; Mackenzie Delta; North America; Northwest Territories https://www.scopus.com/inward/record.uri?eid=2-s2.0-3242769076&doi=10.2118%2f88039-PA&partnerID=40&md5=d7a20515ef2b0ef66b8c5d29ca4440d8 cited By 77 G.J. Moridis article NoAuthor200453 2004 English 01492136 10.2118/0404-0053-jpt Journal of Petroleum Technology 56 Society of Petroleum Engineers (SPE) 53-54 4 https://www.scopus.com/inward/record.uri?eid=2-s2.0-1842831336&doi=10.2118%2f0404-0053-jpt&partnerID=40&md5=68d396766646b87484fb54745d41356f cited By 5 article Carcione200473 We estimate the concentration of gas hydrate at the Mallik 2L-38 research site using P- and S-wave velocities obtained from well logging and vertical seismic profiles (VSP). The theoretical velocities are obtained from a generalization of Gassmann's modulus to three phases (rock frame, gas hydrate and fluid). The dry-rock moduli are estimated from the log profiles, in sections where the rock is assumed to be fully saturated with water. We obtain hydrate concentrations up to 75%, average values of 37% and 21% from the VSP P- and S-wave velocities, respectively, and 60% and 57% from the sonic-log P- and S-wave velocities, respectively. The above averages are similar to estimations obtained from hydrate dissociation modeling and Archie methods. The estimations based on the P-wave velocities are more reliable than those based on the S-wave velocities. © 2004 Elsevier B.V. All rights reserved. 2004 English 09269851 10.1016/j.jappgeo.2004.04.001 Journal of Applied Geophysics 56 73-78 Ist Naz di Oceanogr/di Geofis Sperim, Sgonico, Trieste 34010, Italy 1 Computer simulation; Phosphorus; Rocks; Seismology; Sulfur; Well logging, Dry-rocks; Wave velocities, Gas hydrates, gas hydrate; seismic velocity; seismic wave; vertical seismic profile; well logging, Canada; Mackenzie Delta; North America; Northwest Territories https://www.scopus.com/inward/record.uri?eid=2-s2.0-2942515936&doi=10.1016%2fj.jappgeo.2004.04.001&partnerID=40&md5=078d1c3c547215d4795c8a3a09126ba5 cited By 58 J.M. Carcione D. Gei article Watanabe20042323 To detect the change of physical properties in small areas, a series of high-resolution waveform inversions is applied to time-lapse seismic data. A procedure by use of differentiation between the time-lapse data and normalization using reference data is proposed in this study. The procedure is derived as a straight-forward extension of waveform inversion as the scatterer imaging. Through numerical tests, the proposed approach was found to be more accurate than the conventional approach in obtaining the velocity change in small areas. The method was applied to the time-lapse crosswell seismic data obtained during the Mallik 2002 gas production test. A small area showing a velocity decrease near the production zone were found using the proposed method, indicating the existence of dissociated methane gas in the sand layers. © 2004 Society of Exploration Geophysicists. 2004 English 10523812 10.1190/1.1845221 SEG Technical Program Expanded Abstracts 23 Society of Exploration Geophysicists 2323-2326 Nagoya University, Japan; Japan Petroleum Exploration Co., Ltd, Japan; JGI, Inc, Japan; Kyoto University, Japan 1 Geophysical prospecting; Petroleum prospecting; Seismic response; Seismic waves; Waveform analysis, Conventional approach; Gas production test; Gas-hydrate production; Numerical tests; Production zones; Time-lapse seismic data; Velocity changes; Waveform inversion, Gas hydrates https://www.scopus.com/inward/record.uri?eid=2-s2.0-55849128984&doi=10.1190%2f1.1845221&partnerID=40&md5=b1902cbf1429d2249c4a7392db321581 cited By 74 T. Watanabe S. Shimizu E. Asakawa T. Matsuoka article Taylor2003391 We apply a two-dimensional geothermal model to predict the permafrost and natural gas hydrate structure in theMallik field area, based on two paleoenvironmental scenarios deduced at otherwells in theMackenzieDelta area. ScenarioAindicated a subaerial history throughout theHolocene, and scenario B documented a several thousand year, subaqueous episode during theHolocene followed by recent subaerial exposure. The effects of these histories is limited largely to the 600mthick permafrost zone, with scenarioB predicting a substantial talik. The most defensible scenario can be resolved with ground temperatures or independent paleoenvironmental indicators. The effect of climatewarmingwill be apparent in awarming of the permafrost and, with marine transgression, creation of an underlying talik. Terrestrial methane hydrate deposits remain stable with increasing surface temperatures over several centuries, but the base of gas hydrate stability rises about 2 m after 300 years. 2003 English 00687626 Bulletin of the Geological Survey of Canada 391-401 Geological Survey of Canada, 601 Booth Street, Ottawa, ON, K1A 0E8, Canada 544 https://www.scopus.com/inward/record.uri?eid=2-s2.0-72249115966&partnerID=40&md5=462c6c4ae264f892429da3023a7d1c46 cited By 1 A.E. Taylor article Majorowicz200345 Analysis of data from 32 industrial exploration wells in the Mallik field and surrounding area in the Mackenzie Delta-Beaufort Sea region allowed construction of temperature-depth profiles using regionalheat-flowvalues, temperature at the base ofice-bearing permafrost, and model so thermal conductivity with depth. An analysis of the stability conditions for methane hydrate showed that it is stable in the Mallik field area and that the depth to the base of the methane hydrate stability zone can be as deep as 1500±100minareas of thick permafrost.The depth to the base of the methane hydrate stabilityzone, calculated in this study using reconstructed temperature-depth profiles, was found in a majority of the wells to be 50-150 m deeper than that previously determined using linear temperature profiles and a constant thermal conductivity with depth. 2003 English 00687626 Bulletin of the Geological Survey of Canada 45-56 Northern Geothermal Consultants, 105 Carlson Close, Edmonton, AB, T6R 2J8, Canada; Geological Survey of Canada, 601 Booth Street, Ottawa, ON K1A 0E8, Canada 544 https://www.scopus.com/inward/record.uri?eid=2-s2.0-72249123141&partnerID=40&md5=5ca86d6b0cac044138a715024dfc9617 cited By 1 J.A. Majorowicz S.L. Smith article Rolandone2003 We use temperature profiles from 4 deep (>1600 m) boreholes across Canada to determine ground surface temperature histories (GSTH's) through and after the Last Glacial Maximum (LGM). Inversion yields the temperature history at the base of the glacier and the surface temperature evolution after the glacial retreat. The results indicate geographic differences in basal temperature history across the Ice Sheet. During the Last Glacial Maximum, temperatures at the base of the Ice Sheet were lower in eastern Canada, at the southeastern edge of the glacier, than in central Canada, southwest of the glacier center. At all sites, basal temperatures were above the melting point of ice during and after the LGM, which may explain the highly unstable character of the Ice Sheet. The GSTH's are consistent with information on the history of the Laurentide ice sheet and provide quantitative constraints on glacier flow dynamics. 2003 English 00948276 10.1029/2003GL018046 Geophysical Research Letters 30 American Geophysical Union CRY 3-1 - 3-4 Berkeley Seismological Laboratory, UC Berkeley, 215 McCone Hall, Berkeley, CA 94720, United States; GEOTOP-UQAM-McGill, Ctr. Rech. Geochemie/en Geodynamique, Univ. du Quebec a Montreal, Montréal, H3C 3P8, Canada; Inst. de Physique du Globe de Paris, 4 Place Jussieu, Paris cedex 05 75252, France 18 Boreholes; Glaciers; Ice; Melting; Atmospheric temperature; Glacial geology; Surface properties, Melting points; Borehole temperature; Geographic difference; Ground surface temperature; Last Glacial Maximum; Laurentide ice sheets; Surface temperatures; Temperature history; Temperature profiles, Geophysics; Ice, basal temperature; Last Glacial Maximum; Laurentide Ice Sheet; paleoclimate, North America https://www.scopus.com/inward/record.uri?eid=2-s2.0-0348172344&doi=10.1029%2f2003GL018046&partnerID=40&md5=17fd5a4e2b5b04b5b074e81991bb6d19 cited By 27 F. Rolandone J.-C. Mareschal C. Jaupart article Lee20021711 Elevated elastic velocities are a distinct physical property of gas hydrate-bearing sediments. A number of velocity models and equations (e.g., pore-filling model, cementation model, effective medium theories, weighted equations, and time-average equations) have been used to describe this effect. In particular, the weighted equation and effective medium theory predict reasonably well the elastic properties of unconsolidated gas hydrate-bearing sediments. A weakness of the weighted equation is its use of the empirical relationship of the time-average equation as one element of the equation. One drawback of the effective medium theory is its prediction of unreasonably higher shear-wave velocity at high porosities, so that the predicted velocity ratio does not agree well with the observed velocity ratio. To overcome these weaknesses, a method is proposed, based on Biot-Gassmann theories and assuming the formation velocity ratio (shear to compressional velocity) of an unconsolidated sediment is related to the velocity ratio of the matrix material of the formation and its porosity. Using the Biot coefficient calculated from either the weighted equation or from the effective medium theory, the proposed method accurately predicts the elastic properties of unconsolidated sediments with or without gas hydrate concentration. This method was applied to the observed velocities at the Mallik 2L-39 well, Mackenzie Delta, Canada. 2002 English 00168033 10.1190/1.1527072 Geophysics 67 Society of Exploration Geophysicists 1711-1719 U.S. Geological Survey, Denver Federal Center, Denver, CO 80225, United States 6 Concentration (process); Elasticity; Hydrates; Porosity; Sediments; Acoustic wave velocity; Gas hydrates; Gases; Hydration; Seismic waves; Seismology; Shear waves; Wave propagation, Elastic velocities; Compressional velocities; Effective medium theories; Empirical relationships; Gas hydrate bearing sediments; Gas hydrate concentrations; Shear wave velocity; Solid structures; Unconsolidated sediment, Geophysics; Shear flow, Biot theory; elastic wave; gas hydrate; P-wave; S-wave; velocity https://www.scopus.com/inward/record.uri?eid=2-s2.0-0036867532&doi=10.1190%2f1.1527072&partnerID=40&md5=de885bdfbf6b73789e1cd69d7511f554 cited By 119 M.W. Lee article Dallimore2002 2002 English 00963941 10.1029/2002EO000129 Eos 83 American Geophysical Union 193+198 Geological Survey of Canada, Ottawa, Canada; U.S. Geological Survey, Denver, CO, United States; GeoForschungs Zentrum, Potsdam, Germany; Japan National Oil Corporation, Chiba, Japan 18 https://www.scopus.com/inward/record.uri?eid=2-s2.0-30144442960&doi=10.1029%2f2002EO000129&partnerID=40&md5=d519b792f5d766d246d0843fb5c14057 cited By 7 S.R. Dallimore T.S. Collett M. Weber T. Uchida article Jin2002407 Well logs acquired at the Mallik 2L-38 gas hydrate research well. Mackenzie Delta, Canada, reveal a distinct trend showing that the resistivity of gas-hydrate-bearing sediments increases with increases in density porosities. This trend, opposite to the general trend of decrease in resistivity with porosity, implies that gas hydrates are more concentrated in the higher porosity. Using the Mallik 2L-38 well data, a proportional gas hydrate concentration (PGHC) model, which states that the gas hydrate concentration in the sediment's pore space is linearly proportional to porosity, is proposed for the general habitat of gas hydrate in sediments. Anomalous data (less than 6% of the total data) outside the dominant observed trend can be explained by local geological characteristics. The anomalous data analysis indicates that highly concentrated gas-hydrate-bearing layers would be expected where sediments have high proportions of gravel and coarse sand. Using the parameters in the PGHC model determined from resistivity-porosity logs, it is possible to qualitatively predict the degree of reflection amplitude variations in seismic profiles. Moderate-to-strong reflections are expected for the Mallik 2L-38 well. © 2002 Elsevier Science Ltd. All rights reserved. 2002 English 02648172 10.1016/S0264-8172(02)00011-9 Marine and Petroleum Geology 19 407-415 Korea Ocean Research, Development Institute, Ansan P.O. Box 29, Seoul 425-600, South Korea; US Geological Survey, Denver Federal Center, Box 25046, Denver, CO 80225, United States 4 Pore spaces, Gas hydrates; Porosity; Reflection; Sand; Sediments; Seismic prospecting; Well logging, Geology, amplitude; gas hydrate; porosity; seismic data; seismic reflection; well logging, Canada https://www.scopus.com/inward/record.uri?eid=2-s2.0-0036544514&doi=10.1016%2fS0264-8172%2802%2900011-9&partnerID=40&md5=e8c857b0d3d1c9914fe3d7dc6a763056 cited By 14 Y.K. Jin M.W. Lee T.S. Collett article Guerin2002 The Mallik 2L-38 research well was drilled to 1150 m under the Mackenzie Delta, Canada, and penetrated a subpermafrost interval where methane hydrate occupies up to 80% of the pore space. A suite of high-quality downhole logs was acquired to measure in situ the physical properties of these hydrate-bearing sediments. Similar to other hydrate deposits, resistivity and compressional and shear sonic velocity data increase with higher hydrate saturation owing to electrical insulation of the pore space and stiffening of the sediment framework. In addition, sonic waveforms show strong amplitude losses of both compressional and shear waves in intervals where methane hydrate is observed. We use monopole and dipole waveforms to estimate compressional and shear attenuation. Comparing with hydrate saturation values derived from the resistivity log, we observe a linear increase in both attenuation measurements with increasing hydrate saturation, which is not intuitive for stiffening sediments. Numerical modeling of the waveforms allows us to reproduce the recorded waveforms and illustrate these results. We also use a model for wave propagation in frozen porous media to explain qualitatively the loss of sonic waveform amplitude in hydrate-bearing sediments. We suggest that this model can be improved and extended, allowing hydrate saturation to be quantified from attenuation measurements in similar environments and providing new insight into how hydrate and its sediment host interact. 2002 English 21699313 Journal of Geophysical Research: Solid Earth 107 Blackwell Publishing Ltd EPM 1-1 - EPM 1-12 Borehole Research Group, Lamont-Doherty Earth Observatory, Palisades, NY, United States 5 acoustic logging; gas hydrate; porous medium; wave propagation; well logging, Canada; Mackenzie Delta https://www.scopus.com/inward/record.uri?eid=2-s2.0-0037053547&partnerID=40&md5=48987f68a276606dd2157237245ba706 cited By 139 G. Guerin D. Goldberg article Lee2001763 Downhole-measured compressional- and shear-wave velocities acquired in the Mallik 2L-38 gas hydrate research well, northwestern Canada, reveal that the dominant effect of gas hydrate on the elastic properties of gas hydrate-bearing sediments is as a pore-filling constituent. As opposed to high elastic velocities predicted from a cementation theory, whereby a small amount of gas hydrate in the pore space significantly increases the elastic velocities, the velocity increase from gas hydrate saturation in the sediment pore space is small. Both the effective medium theory and a weighted equation predict a slight increase of velocities from gas hydrate concentration, similar to the field-observed velocities; however, the weighted equation more accurately describes the compressional- and shear-wave velocities of gas hydrate-bearing sediments. A decrease of Poisson's ratio with an increase in the gas hydrate concentration is similar to a decrease of Poisson's ratio with a decrease in the sediment porosity. Poisson's ratios greater than 0.33 for gas hydrate-bearing sediments imply the unconsolidated nature of gas hydrate-bearing sediments at this well site. The seismic characteristics of gas hydrate-bearing sediments at this site can be used to compare and evaluate other gas hydrate-bearing sediments in the Arctic. 2001 English 00168033 10.1190/1.1444966 Geophysics 66 Society of Exploration Geophysicists 763-771 U.S. Geological Survey, Denver Federal Center, Box 25046, MS 939, Denver, Colorado 80225, United States 3 Elasticity; Hydrates; Pore size; Sediments; Velocity; Gases; Hydration; Poisson ratio; Shear flow; Shear waves, Hydrate-bearing sediments; Compressional; Effective medium theories; Elastic properties; Gas hydrate bearing sediments; Gas hydrate concentrations; Gas hydrate saturations; Sediment porosities; Shear wave velocity, Geophysics; Gas hydrates, elastic property; gas hydrate; P-wave; S-wave; sediment; seismic velocity https://www.scopus.com/inward/record.uri?eid=2-s2.0-0035328506&doi=10.1190%2f1.1444966&partnerID=40&md5=db28418584bf04d929f35d6d1274fab7 cited By 82 M.W. Lee T.S. Collett article Winters200094 As part of an interdisciplinary field program, a 1150-m deep well was drilled in the Canadian Arctic to determine, among other goals, the location, characteristics, and properties of gas hydrate. Numerous physical properties of the host sediment were measured in the laboratory and are presented in relation to the lithology and quantity of in situ gas hydrate. Profiles of measured and derived properties presented from that investigation include: sediment wet bulk density, water content, porosity, grain density, salinity, gas hydrate content (percent occupancy of non-sediment grain void space), grain size, porosity, and post-recovery core temperature. The greatest concentration of gas hydrate is located within sand and gravel deposits between 897 and 922 m. Silty sediment between 926 and 952 m contained substantially less, or no, gas hydrate perhaps because of smaller pore size. 2000 English 00778923 10.1111/j.1749-6632.2000.tb06762.x Annals of the New York Academy of Sciences 912 New York Academy of Sciences 94-100 U.S. Geological Survey, 384 Woods Hole Road, Woods Hole, MA 02543, United States; Geological Survey of Canada, Ottawa, Ont. K1A 0E8, Canada; U.S. Geological Survey, Denver, CO 25046, United States; Geological Survey of Canada, Dartmouth, NS B2Y 4A2, Canada; Japan Petroleum Exploration Company, Mihama-ku Chiba, Japan methane; natural gas, Arctic; Canada; conference paper; gas; gas analysis; porosity; river; salinity; sand; sediment; temperature; water content https://www.scopus.com/inward/record.uri?eid=2-s2.0-0033940146&doi=10.1111%2fj.1749-6632.2000.tb06762.x&partnerID=40&md5=15bb2c4b8ec3a1b40a0b1f9de5e11297 cited By 9 W.J. Winters S.R. Dallimore T.S. Collett K.A. Jenner J.T. Katsube R.E. Cranston J.F. Wright F.M. Nixon T. Uchida article Tulk2000859 Raman spectroscopy is reviewed with particular emphasis placed on its application to gas hydrates. Experimental examples discussed include studies of the totally symmetric C-H stretching vibration v1 (A1) of methane in both synthetic and natural hydrate samples (from the JAPEX/JNOC/GSC Mallik 2L-38 research well); a comparison of the coupled O-H vibrations of water in the host lattice of CH4 hydrate and ice I(h) at low temperature; and local structural details of the relaxation of the hydrogen-bonded water on crystallization to structure II hydrate of amorphous tetrahydrofuran (THF) aqueous solutions. This paper is intended to be an introduction to Raman spectroscopy with specific examples from research at the National Research Council of Canada, and is aimed at those who wish to apply the technique as a tool to investigate gas hydrates. 2000 English 00778923 10.1111/j.1749-6632.2000.tb06840.x Annals of the New York Academy of Sciences 912 New York Academy of Sciences 859-872 Steacie Inst. for Molecular Sciences, National Research Council of Canada, Ottawa, Ont. K1A 0R6, Canada methane; water, aqueous solution; conference paper; crystallization; gas; gas analysis; Raman spectrometry https://www.scopus.com/inward/record.uri?eid=2-s2.0-0033941607&doi=10.1111%2fj.1749-6632.2000.tb06840.x&partnerID=40&md5=0e64a32a74bfdcc07d2787ee755f0d47 cited By 86 C.A. Tulk J.A. Ripmeester D.D. Klug article Hyde20001347 In conjunction with the 1998 Mallik 2L-38 gas-hydrate research well program (Dallimore et al, 1999), two time-domain electromagnetic sounding profiles were surveyed in an attempt to delineate a known gas-hydrate zone at depth. The research well is located on Richard's Island in the Mackenzie Delta, Northwest Territories. Electrical resistivity logging at the Mallik site in 1972 and 1998 defined a resistive zone from 900 m to 1100 m coincident with a gas-hydrate zone lying within unfrozen and electrically conductive sediments. A resistive layer, interpreted as the gas-hydrate zone was detected by the TEM survey at all soundings except for those overlain by thin permafrost and a thick unfrozen zone. This thin permafrost/thick unfrozen zone assemblage resulted in greater than expected conductivity-thickness product and limited the depth investigation of the survey. In addition, late-time negative transients interpreted as induced polarization effects, obscured the clear detection of gas hydrates. © 2000 Society of Exploration Geophysicists. 2000 English 10523812 10.1190/1.1815647 SEG Technical Program Expanded Abstracts 19 Society of Exploration Geophysicists 1347-1350 Terrain Sciences, Geological Survey of Canada, Canada 1 Electric logging; Gases; Hydration; Permafrost; Petroleum prospecting; Surveys, Electrically conductive; Hydrate zones; Induced polarization; Resistive zones; TEM surveys; Time domain electromagnetics, Gas hydrates https://www.scopus.com/inward/record.uri?eid=2-s2.0-84955067779&doi=10.1190%2f1.1815647&partnerID=40&md5=2dd2d5b00c910d3138883dab6bf6e7e3 cited By 0 C. Hyde S. Dallimore J. Hunter M. Douma R. Good R. Burns article Lee2000179 One of the distinct physical properties of gas-hydrate-bearing sediments is elevated seismic velocities. A number of velocity models and equations have been presented to describe the effect of gas hydrate on the seismic velocities; e.g., pore-filling model, cementation model, effective medium theory, a weighted equation, and time-average equation. The data set from Mallik 2L-38 gas hydrate research well drilled in northern Canada provided us a unique opportunity to test the velocity models for gas-hydrate-bearing sediments. Velocities predicted from an effective medium theory and those from a weighted equation are compared with observed well log velocities. In the case where there is no gas hydrate in the pore space, P-wave velocities predicted from the effective medium theory are lower than those from the weighted equation when porosity is less than about 30% and higher when porosity is higher than about 30%. For S-waves, effective medium theory predicts generally higher velocities than those from the weighted equation. Both theories predict similar increases in P- and S-wave velocities when gas hydrate occupies the pore space. Even though gas hydrate concentration in the pore space is not known accurately, analyses using both P- and S-wave velocities and their ratios enable us to test the validity of velocity models. Considering only P-wave velocities, there is not much difference between the effective medium and weighted equation. However, considering both P- and S-wave velocities and their ratios, the weighted equation is preferred to the effective medium theory in predicting elastic wave velocities for gas-hydrate-bearing sediments at the Mallik 2L-38 well. © 2001 by the American Geophysical Union. 2000 English 9781118668412; 9780875909820 00658448 10.1029/GM124p0179 Geophysical Monograph Series 124 Blackwell Publishing Ltd Dillon W.P., Paull C.K. 179-187 U.S. Geological Survey, Denver Federal Center, P.O. Box 25046, MS 939, Denver, CO 80225, United States https://www.scopus.com/inward/record.uri?eid=2-s2.0-85040236589&doi=10.1029%2fGM124p0179&partnerID=40&md5=daa3c7b9c0ff823cdec3cf318b879f4b cited By 18 M.W. Lee T.S. Collett article Uchida20001021 The JAPEX/JNOC/GSC Mallik 2L-38 research well was drilled to a depth of 1150 m beneath the permafrost zone in the Mackenzie Delta, N.W.T., Canada, early in 1998. A large amount of natural gas hydrates were successfully retrieved from a variety of sandy and gravel sediments. Over 110 m of gas hydrate-bearing sediments were found to be distributed between 897 m and 1100 m deep. Approximately 37 meters of core were recovered in this interval with most of the recovered gas hydrates being less than 2 mm in size occurring mainly in intergranular porosity of silty to clean massive sand and conglomerate (granule to pebble). Typically, hydrate-bearing strata were between 10 cm and more than one meter thick with an estimated porosity of 25 to 35%. The largest form of hydrate was about 2 cm in diameter, occurring as clasts and intergranular porosity within granular sands. Occurrences of natural gas hydrate have been observed visually at the drill site and in core samples preserved in pressurized storage vessels utilizing an X-ray CT scanner technique. Quantitative assessments of gas hydrate concentrations in core samples have been made based on pressure response of dissociation vessels and direct volumetric measurements. Six types of gas hydrate have been recognized: (1) pore-space hydrate, (2) platy hydrate, (3) layered/massive hydrate, (4) disseminated hydrate, (5) nodule hydrate, and (6) vein/dyke hydrate. The X-ray CT images proved useful for characterizing macroscopic forms of gas hydrate. Finer grained occurrences were more difficult to study, however the distribution of gas hydrates and granular grains ran be recognized. The occurrences of natural gas hydrates in the Mallik well are compared to the previous natural gas hydrate core samples obtained from ODP/DSDP programs and other field studies. 2000 English 00778923 10.1111/j.1749-6632.2000.tb06857.x Annals of the New York Academy of Sciences 912 New York Academy of Sciences 1021-1033 JAPEX Research Center, 1-2-1 Hamada, Mihama, Chiba 261-0025, Japan; Geologicai Survey of Canada, 601 Booth Street, Ottawa, Ont. K1A 0E8, Canada methane; natural gas, Canada; computer assisted tomography; conference paper; gas; gas analysis; oil industry; porosity; sand; sediment; X ray analysis https://www.scopus.com/inward/record.uri?eid=2-s2.0-0033941353&doi=10.1111%2fj.1749-6632.2000.tb06857.x&partnerID=40&md5=27d7994047bfa60edc0ae655ef3c73bc cited By 34 T. Uchida S. Dallimore J. Mikami article Mikami20001011 Core samples containing pore-spare gas hydrate within granular sands were collected from 913.76 m of the research well named JAPEX/JNOC/GSC Mallik 2L-38. X-ray CT images of the core were acquired while warming from -18 to 4°C, and subsequently during stepped decreases of 0.1 MPa in the chamber pressure below the methane hydrate equilibrium pressure. Discharged gas flows and sample temperatures were monitored continuously. Changes in CT values indicated that gas hydrate dissociated simultaneously both on the exposed surfaces and within the pore spaces of the sample in response to pressure changes. This suggested that pressure reductions were effectively transmitted through the sample most likely because the samples contained some amount of fluids. The result of gas flow measurements indicated that a larger pressure drawdown caused a higher dissociation rate. 2000 English 00778923 10.1111/j.1749-6632.2000.tb06856.x Annals of the New York Academy of Sciences 912 New York Academy of Sciences 1011-1020 JAPEX Research Center, 1-2-1 Hamada, Mihama-ku, Chiba 261-0025, Japan; Department of Geosystem Engineering, University of Tokyo, 7-3-1 Hongou, Bunkyo-ku, Tokyo 113-8656, Japan; Teikoku Oil Company, 1-31-10 Hatagaya, Shibuya-ku, Tokyo 151-0072, Japan methane; natural gas, computer assisted tomography; conference paper; dissociation; gas; gas flow; pressure; sand; temperature; X ray analysis https://www.scopus.com/inward/record.uri?eid=2-s2.0-0033926433&doi=10.1111%2fj.1749-6632.2000.tb06856.x&partnerID=40&md5=75b1e302735ab2088623d389bab36185 cited By 21 J. Mikami Y. Masuda T. Uchida T. Satoh H. Takeda article Ohara2000733 The Mallik 2L-38 well was drilled in February and March, 1998 to a depth of 1150m at a site located in the Mackenzie Delta, N. W. T., Canada. Undertaken as a collaborative agreement between the Japan National Oil Corporation and the Geological Survey of Canada, the well was conducted as a research and development project with engineering goals to evaluate various technologies for drilling and coring gas-hydrate-bearing strata. The Mallik site was chosen as it had favorable logistics and was though to contain a thick interval of gas hydrates between 897 and 1110 m depth. Drilling operation included a surface hole (with 8 coring runs) to 687m for installation of a 340mm surface casing, and a main hole (with 16 coring runs) to the target depth of 1150m. The drilling system utilized a KCl/polymer drilling mud that was cooled to 2°C using a plate type heat exchanger. Drilltreat, a chemical mud additive was used in the main hole to stabilize the hydrate within drill cuttings and formation sediments. Drilling operations were conducted without any serious hole problems, accidents, or mishaps. However, delays were caused by adverse weather and mechanical problems, causing adjustments in the overall program. Coring in the main hole was particularly successful allowing evaluation of four different core barrels. Gas-hydrate-bearing core was collected in a variety of sediments between 886 and 952m. The excellent condition of the core samples, controlled gas hydrate dissociation within the mud column, and near-gauge hole, confirmed that the combination of chilled mud with Drilltreat performed extremity well. 2000 English 9781555633493 10.2523/59795-ms SPE Proceedings - Gas Technology Symposium Soc Pet Eng (SPE), Richardson 733-742 Japan Petroleum Exploration Co, Ltd, Japan Additives; Gas hydrates; Heat exchangers; Mud logging; Natural gas well drilling; Oil field development; Organic polymers; Petroleum industry; Petroleum prospecting; Potassium compounds; Sediments; Societies and institutions, Chemical mud additive; Coring; Coring gas hydrate bearing strata; Polymer drilling mud; Potassium chloride drilling mud, Natural gas fields https://www.scopus.com/inward/record.uri?eid=2-s2.0-0033688165&doi=10.2523%2f59795-ms&partnerID=40&md5=edb43bb0a8093b0ca4a366f802b15bb2 cited By 8 T. Ohara S.R. Dallimore E. Fercho article Dallimore199911 The JAPEX/JNOC/GSC Mallik 2L-38 gas hydrate research well was drilled in February and March, 1998, in the Mackenzie Delta, Northwest Territories, Canada, to a depth of 1150 m. The scientific program was conducted through a collaborative agreement between the Japan National Oil Corporation and the Geological Survey of Canada with key participation by the Japan Petroleum Exploration Company and the United States Geological Survey. A primary objective of the well was to undertake a comprehensive scientific research program to study an arctic gas hydrate accumulation. Field research conducted as part of the Mallik 2L-38 program included collection of permafrost and gas-hydrate-bearing core samples, downhole geophysical logging, and a vertical seismic profile survey. Laboratory and modelling studies undertaken during the field program, and subsequently as part of a post-field research program, documented the sedimentology, biostratigraphy, physical/petrophysical properties, pore-water and gas geochemistry, geophysics, and reservoir characteristics of the Mallik field gas hydrate accumulation. 1999 English 00687626 Bulletin of the Geological Survey of Canada 11-17 Geological Survey of Canada, 601 Booth Street, Ottawa, Ont. K1A 0E8, Canada 544 https://www.scopus.com/inward/record.uri?eid=2-s2.0-3442901587&partnerID=40&md5=7eed157529b8c688bdbcf2e63c3360ec cited By 25 S.R. Dallimore article Walia1999341 As part of the JAPEX/JNOC/GSC Mallik 2L-38 field program, a vertical seismic profiling(VSP) survey was carried out at zero and offset-source positions with multicomponent receiver tools and multipolarized vibrators. The results will be integrated with downhole logs and regional seismic data to evaluate the effect of gas hydrate on seismic velocity and to estimate gas hydrate concentrations. The excellent data quality allows accurate compressional-and shear-velocity depth profiles. There are down-going and up-going waves from numerous reflectors, and corridor stacks provide comparison with surface multi-channel data. Velocities in the permafrost zone above 600 m are enhanced, to more than 2500 m/s. In the largely unfrozen section from 600 m to 850 m, the velocities are lower, about 2000 m/s. The gas hydrate zone is well defined below about 900 m, with velocities of 2500-2700 m/s. Poisson's Ratio is ∼0.39 in both the permafrost and gas hydrate sections, compared to -0.44 in the unfrozen sections. 1999 English 00687626 Bulletin of the Geological Survey of Canada 341-355 CGG Geophysics Canada, 404 6th Avenue S.W., Calgary, Alta. T2P 0R9, Canada 544 https://www.scopus.com/inward/record.uri?eid=2-s2.0-2942571807&partnerID=40&md5=7e9d9f67300e8758819ea6d6018c4ef5 cited By 6 R. Walia article Sakai1999323 A VSP survey was conducted at the JAPEX/JNOC/GSC Mallik 2L-38 gas hydrate research well to determine elastic-wave velocities that were estimated by traveltime inversion of zero-offset VSP and wavefield inversion of offset VSP data. Shear-wave velocity is estimated to be slower from VSP data than from wireline DSI measurements in the depth interval from 677 m to 889 m. The compressional-wave velocity difference between the VSP- and DSI-derived velocities are comparatively small. Synthetic seismograms from the drift-corrected DSI velocity log correlate well with VSP sections, especially for compressional waves. Azimuthal anisotropy is suggested in VSP shear-source data and the mode of anisotropy appears to change around the base of permafrost. By comparing computed elastic velocities with drift-corrected DSI velocity logs, two opposing gas hydrate saturation models are examined. Shear wave velocity proved to be the key data to select the correct model. The observed elastic velocity fits the computed elastic velocity for the model of gas hydrate disseminated in pore-space with little cementation at the grain boundaries. 1999 English 00687626 Bulletin of the Geological Survey of Canada 323-340 Japan Petroleum Exploration Company, Ltd. (JAPEX), 2-2-20 Higashi-shinagawa, Shinagawa-ku, Tokyo 140-0002, Japan 544 https://www.scopus.com/inward/record.uri?eid=2-s2.0-0001817391&partnerID=40&md5=c6df09a151fc041c9a94540a522fa0c8 cited By 42 A. Sakai article Uchida1999205 The JAPEX/JNOC/GSC Mallik 2L-38 gas hydrate research well was drilled to a depth of 1150 m in the Mackenzie Delta, Northwest Territories, Canada, in February and March, 1998. A highlight of the project was the successful retrieval of natural gas hydrate samples in a variety of sediments. A summary is presented of research conducted by the Japanese research consortium led by the Japan National Oil Corporation with participation by ten Japanese companies and institutes. Fingerprints of the gas hydrate crystal structure and the molar ratio of water to guest-gas molecules occupying lattice sites are described for gas-hydrate-bearing samples as obtained by NMR and Raman spectroscopy. X-Ray CT imagery is used to describe the texture and gas hydrate/sediment characteristics of recovered samples during controlled dissociation testing. In addition, inorganic and organic chemical, thermal geophysical, and physical properties are described for key core horizons. Results are also presented documenting the rate of gas hydrate dissociation in drilling fluids with different chemistry including lecithin. 1999 English 00687626 Bulletin of the Geological Survey of Canada 205-228 JAPEX Research Center, Japan Petroleum Exploration Company, Ltd., 1-2-1 Hamada, Mihama-ku, Chiba 261-0025, Japan 544 https://www.scopus.com/inward/record.uri?eid=2-s2.0-27844564294&partnerID=40&md5=35c2a611c6e39ae7ac892cdb4d13b553 cited By 15 T. Uchida article Collett1999357 The gas hydrate stability zone is areally extensive beneath most of the Mackenzie Delta-Beaufort Sea region, with the base of the gas hydrate stability zone more than 1000 m deep on Richards Island. In this study, gas hydrate has been inferred to occur in nine Richards Island exploratory wells on the basis of well-log responses calibrated to the response of the logs within the cored gas-hydrate-bearing intervals of the JAPEX/JNOC/GSC Mallik 2L-38 gas hydrate research well. The integration of the available well-log data with more than 240 km of industry-acquired reflection seismic data have allowed us to map the occurrence of four significant gas hydrate and associated free-gas accumulations in the Ivik-Mallik-Taglu area on Richards Island. The occurrence of gas hydrate on Richards Island is mostly restricted to the crest of large anticlinal features that cut across the base of the gas hydrate stability zone. Combined seismic and well-log data analysis indicate that the known and inferred gas hydrate accumulations on Richards Island may contain as much as 187 178106 m3 of gas. 1999 English 00687626 Bulletin of the Geological Survey of Canada 357-376 United States Geological Survey, Denver Federal Center, MS-939, Denver, CO 80225, United States 544 https://www.scopus.com/inward/record.uri?eid=2-s2.0-27844537822&partnerID=40&md5=73eae20cb50ac4546342de11dc9eef9a cited By 26 T.S. Collett article Jenner199957 A detailed sedimentological program has been conducted on gas-hydrate-bearing core samples from the JAPEX/JNOC/GSC Mallik 2L-38 gas hydrate research well. Three structurally and texturally distinct sedimentary facies are identified. Facies Csc (952.2-926.5 m) is a weakly bioturbated, clayey silt interbedded with fissile coal and silty sand. Facies Sg (926.5-908.5 m) is comprised of interbedded, finingupward successions of matrix-supported gravel to pebbly sand and fine sand. A dolomite-cemented sandstone (926.5-925 m) forms a distinct basal subfacies (Sst). Facies Ss (908.5-886.2 m) is a fine- to mediumgrained sand interbedded with gravel which fines upward to fine-grained sand with a gradational increase in silt content. The Kugmallit-Mackenzie Bay sequence boundary is interpreted to occur at the base of facies Sg. In situ and self-preserved gas hydrate occurred mainly in the sands and gravels of the Sg and Ss facies. The dolomite-cemented sandstone (subfacies Sst) may be related to complementary geochemical environments resulting from the formation of authigenic pyrite and solute exclusion related to gas hydrate growth within facies Sg. 1999 English 00687626 Bulletin of the Geological Survey of Canada 57-68 Geological Survey of Canada (Atlantic), P.O. Box 1006, Dartmouth, NS B2Y 4A2, Canada 544 https://www.scopus.com/inward/record.uri?eid=2-s2.0-27844552879&partnerID=40&md5=dd75d13cb21dfa2cf7eabed58445e00b cited By 14 K.A. Jenner article Dallimore199931 The occurrence of natural gas hydrate within Cenozoic sediments of the Mackenzie Delta-Beaufort Sea region has been well documented. In preparation for the JAPEX/JNOC/GSC Mallik 2L-38 gas hydrate research well, a detailed evaluation of terrestrial gas hydrate occurrences was undertaken to assess the geological setting, sediment associations, pressure and temperature conditions, and the presence of free gas in the Mackenzie Delta-Beaufort Sea region. After an exhaustive review, it was determined that the Mallik L-38 site, drilled by Imperial Oil in 1972, offered the highest probability of encountering a thick gas hydrate occurrence with high gas hydrate concentrations. On the basis of openhole well-log evaluation, it was estimated that about Him of gas-hydrate-bearing strata occur at this location from 810.1 to 1102.3 m, within the zone of predicted methane hydrate stability and below the base of icebearing permafrost, estimated to be at 640 m. 1999 English 00687626 Bulletin of the Geological Survey of Canada 31-43 Geological Survey of Canada, 601 Booth Street, Ottawa, Ont. K1A 0E8, Canada 544 https://www.scopus.com/inward/record.uri?eid=2-s2.0-27844491511&partnerID=40&md5=4b68ff0fc6d57e636fd5ea0e73a5f1ee cited By 47 S.R. Dallimore article Winters1999241 As part of an ongoing laboratory study, preliminary acoustic, strength, and hydraulic conductivity results are presented from a suite of tests conducted on four natural-gas-hydrate-containing samples from the Mackenzie Delta JAPEX/JNOC/GSC Mallik 2L-38 gas hydrate research well. The gas hydrate samples were preserved in pressure vessels during transport from the Northwest Territories to Woods Hole, Massachusetts, where multistep tests were performed using GHASTLI (Gas Hydrate And Sediment Test Laboratory Instrument), which recreates pressure and temperature conditions that are stable for gas hydrate. Properties and changes in sediment behaviour were measured before, during, and after controlled gas hydrate dissociation. Significant amounts of gas hydrate occupied the sample pores and substantially increased acoustic velocity and shear strength. 1999 English 00687626 Bulletin of the Geological Survey of Canada 241-250 United States Geological Survey, Center for Coastal and Marine Geology, 384 Woods Hole Road, Woods Hole, MA 02543, United States 544 https://www.scopus.com/inward/record.uri?eid=2-s2.0-0013261763&partnerID=40&md5=8710460ee327df6188790aa06b040820 cited By 34 W.J. Winters article Khairkhah1999377 Immense volumes of naturally occurring gas hydrate in different parts of the world, onshore and offshore, have encouraged the belief that gas hydrate in the next century may become a viable energy resource. Various issues need to be resolved to convert gas hydrate from an energy resource to an energy reserve of real commercial value. The production capability of a gas hydrate reservoir and the gas production technique that could be utilized should be addressed through geological and petrophysical studies, well-production tests and reservoir simulation. To make the simulation of practical value, the controlling mechanisms of fluid flow, kinetics, and heat transfer should be incorporated in the model. The Mallik gas hydrate accumulation in the Mackenzie Delta has exhibited promising potential to be considered a gas reserve through the assessments made of the Mallik L-38 and 2L-38 wells. The data available from both wells and the results of production tests in JAPEX/JNOC/GSC Mallik L-38 gas hydrate research well accommodate basic requirements for comprehensive modelling of the reservoir and production of gas from the in situ gas hydrate through various methods. 1999 English 00687626 Bulletin of the Geological Survey of Canada 377-390 University of Calgary, 2500 University Drive N.W., Calgary, Alta. T2N 1N4, Canada 544 https://www.scopus.com/inward/record.uri?eid=2-s2.0-0003274682&partnerID=40&md5=f6cafb6b1282871d5d12e8ae5ee42ff5 cited By 6 D. Khairkhah article Cranston1999165 A pore-water research program was designed to measure dissolved components in interstitial water from sediment core samples collected during the JAPEX/JNOC/GSC Mallik 2L-38 gas hydrate research-well project. Pore waters from the gas-hydrate-bearing samples had an average salinity of 8 ppt compared to 34 ppt for non-gas-hydrate-bearing samples. The difference in salinities suggests that 80-90% of the pore space in the gas-hydrate-bearing sediment was filled with gas hydrate, which dissociated during recovery. Potassium concentration was also measured in pore water, to estimate the amount of drill-mud contamination in pore-water samples, since the drill mud contained brine solution made from potassium chloride. On average, pore-water salinities were estimated to be enhanced by 2 ppt due to drill-mud contamination. 1999 English 00687626 Bulletin of the Geological Survey of Canada 165-175 Geological Survey of Canada (Atlantic), P.O. Box 1006, Dartmouth, NS B2Y 4A2, Canada 544 https://www.scopus.com/inward/record.uri?eid=2-s2.0-4644339220&partnerID=40&md5=44b2d12fc91a388b1f04b62b9cf68ffc cited By 20 R.E. Cranston article Winters199995 A 1150 m deep gas hydrate research well was drilled in the Canadian Arctic in February and March 1998 to investigate the interaction between the presence of gas hydrate and the natural conditions presented by the host sediments. Profiles of the following measured and derived properties are presented from that investigation: water content, sediment wet bulk density, grain size, porosity, gas hydrate quantity, and salinity. These data indicate that the greatest concentration of gas hydrate is located within sand and gravel deposits between 897 m and 922 m. American Society for Testing and Materials 1997: Standard test method for specific gravity of soil solids by gas pycnometer D 5550-94; in American Society for Testing and Materials, Annual Book of ASTM Standards, v. 04.09, Soil and Rock, West Conshohocken, Pennsylvania, p. 380-383. 1999 English 00687626 Bulletin of the Geological Survey of Canada 95-100 United States Geological Survey, Center for Coastal and Marine Geology, 384 Woods Hole Road, Woods Hole, MA 02543, United States 544 https://www.scopus.com/inward/record.uri?eid=2-s2.0-0008529457&partnerID=40&md5=bb8055e1b27dbc38c647619f4e21d378 cited By 34 W.J. Winters article Katsube1999109 A petrophysical study has been performed on mudstone and sandstone samples from depths of 880-950 m to determine the petrophysical controls on gas hydrate distribution in the sedimentary sequence at the J APEX/JNOC/GSC Mallik 2L-38 well site, Northwest Territories, Canada. Within the cored interval of the Mallik 2L-38 well gas hydrate is hosted in two sandstone horizons with overlying and underlying mudstone horizons, with minor gas hydrate concentrations within some mudstone formations. Results indicate that, although the interbedded mudstone units have relatively high porosities (24-30%) and are at relatively shallow depths, they have a well developed framework-supported texture, probably due to high silt and sand content (56-78 weight per cent), and a maximum burial depth greater than present. Regardless of this, the minor matrix content (13-25 weight per cent) controls the fluid transport characteristics, resulting in extremely low mudstone permeability sections (2×10-21 m to 2×10-19 m2). There are indications that these low permeabilities and the storage pore sizes contribute to the gas hydrate distribution. 1999 English 00687626 Bulletin of the Geological Survey of Canada 109-124 Geological Survey of Canada, 601 Booth Street, Ottawa, Ont. K1A 0E8, Canada 544 https://www.scopus.com/inward/record.uri?eid=2-s2.0-8744238665&partnerID=40&md5=21203f8abc443e4c7429c7f10438bdba cited By 13 T.J. Katsube article White199981 The JAPEX/JNOC/GSC Mallik 2L-38 gas hydrate research well was drilled in 1998 to investigate the geological, geochemical, geophysical, and engineering properties of a gas hydrate accumulation previously identified in the Mallik L-38 well. Palynological analysis of core and cuttings from 670 m to 1150 m (TD) are reported here. Detailed quantitative analysis has been done on the 886-952 m cored interval that hosts the main gas hydrate accumulation. The pollen and spore evidence suggests the following biostratigraphic subdivisions for the 670-1150 m succession: 670-785 m, Late Miocene or older; 775-897 m, within the range of Early Miocene to Late Eocene; 897-930 m, probably Late Eocene; 930-995 m, Late Eocene; and 995-1151m within the range Early to Middle Eocene. Below 930 m the rocks are best assigned to the Richards and upper Taglu sequences. A dominantly continental succession is indicated, with a marginal marine and/or estuarine episode between about 945 m and 948 m, in the Late Eocene. The dinoflagellates in this interval are considered to be indigenous to the sampled rock. There is evidence of two episodes of edaphic-climatic dryness in the Late Eocene and probable Late Eocene. 1999 English 00687626 Bulletin of the Geological Survey of Canada 81-93 Geological Survey of Canada (Calgary), 3303-33rd Street N.W., Calgary, Alta. T2L 2A7, Canada 544 Dinophyceae https://www.scopus.com/inward/record.uri?eid=2-s2.0-27844456805&partnerID=40&md5=ea401d462158017e5c255465864fc498 cited By 3 J.M. White article McNeil199969 Core and cuttings samples from the JAPEX/JNOC/GSC Mallik 2L-38 gas hydrate research well in the Mackenzie Delta have yielded sparse terrestrial microfossils and abundant reworked Cretaceous foraminifers (silicified) and plant microfossils. No definitely in situ marine microfossils were recovered in the borehole (total depth 1150m; gas hydrate at 896-1110m). Cores from 110-118 m and 173-175 m contained terrestrial microfossils including fungi, seeds, insect fragments, and abundant macerated plant fragments typical of the Pliocene-Pleistocene Iperk Sequence in the Mackenzie-Beaufort Basin. Core from 886-951 m and cuttings samples from 670-870 and 960-1140 m yielded reworked algal cysts, seed casings, and megaspores. In addition, cuttings contained reworked Cretaceous agglutinated foraminifers. Core and cuttings samples were also characterized by quartz, chert, brownish-black lignite, coaly fragments, and rare amber. The lithology of the section below 670 m is characteristic of the Oligocene Kugmallit Sequence in the Mackenzie-Beaufort Basin. 1999 English 00687626 Bulletin of the Geological Survey of Canada 69-75 Geological Survey of Canada (Calgary), 3303-33rd Street N.W., Calgary, Alta. T2L 2A7, Canada 544 algae; Foraminifera; Fungi; Hexapoda https://www.scopus.com/inward/record.uri?eid=2-s2.0-27844533982&partnerID=40&md5=cf4eb63b19f08e56c32a96acd5776239 cited By 2 D.H. McNeil article Uchida1999197 The JAPEX/JNOC/GSC Mallik 2L-38 gas hydrate research well was drilled through a thick interbedded sequence of gas-hydrate-bearing sediments between 896 and 1106 m. In total, 37.3 m of core were collected between 886 and 952.6 m, using a variety of coring systems. Visual observations at the drill site identified a predominance of pore-space gas hydrate in varying concentrations within framework-supported sands and pebbly sands. Gas hydrate was mainly fine grained (<2 mm), filling the intergranular pores and/or coating mineral grains. Although rare, thin veins (1-2 mm) and clasts or nodules of gas hydrate (up to 0.5 mm) were also observed. The largest gas hydrate occurrence (2 cm in diameter) formed the matrix of a granular sand at 913 m. X-ray CT imagery, carried out in Japan, has identified eight well constrained signatures of the constituent components of the gas-hydrate-bearing sands and granular sands. These images have been used to establish textural characteristics and the relationship between sediment grains and gas hydrate. 1999 English 00687626 Bulletin of the Geological Survey of Canada 197-204 JAPEX Research Center, Japan Petroleum Exploration Company, Ltd., 1 -2-1 Hamada, Mihama-ku, Chiba 261-0025, Japan 544 https://www.scopus.com/inward/record.uri?eid=2-s2.0-2142665479&partnerID=40&md5=c4a0e78b48ab3eb225f233092c5f02c7 cited By 9 T. Uchida article Colwell1999189 Microbial cell distribution in sediment core samples from the JAPEX/JNOC/GSC Mallik 2L-38 gas hydrate research well on the Mackenzie Delta (Canada) was studied using acridine orange direct counts of stained cells for total cell estimation, and by most probable number statistical enumeration for culturable methanogens. The purpose was to characterize the microbial communities in gas-hydrate-bearing sediments. Results indicated that the total cell count values were in the range of 1.1 × 105 cells/g to 2.8× 106 cells/g with culturable methanogens present at 1×10-4% to 1.0% of those values. These results also indicated that culturable methanogens may be more numerous in the porous sandy strata of the Mackenzie Bay Sequence than in clay and silt units of the Kugmallit Sequence. These data expand the known distribution of methanogens in deep sediments and establish the presence of microbial communities in subpermafrost environments. 1999 English 00687626 Bulletin of the Geological Survey of Canada 189-195 Biotechnologies Department, Idaho National Engineering and Environmental Laboratory, P.O. Box 1625, Idaho Falls, ID 83415-2203, United States 544 https://www.scopus.com/inward/record.uri?eid=2-s2.0-27844592645&partnerID=40&md5=6fc38e28c2995fca4d7c6c1e1627173d cited By 7 F.S. Colwell article Snowdon1999125 Optimized, first-order, discrete Arrhenius kinetic parameters have been determined for the thermogenic generation of methane and carbon dioxide for several low-maturity, organic-rich core samples from the JAPEX/JNOC/GSC Mallik 2L-38 gas hydrate research well. Pyrolysis was carried out using a thermogravimetric analyzer heated at 10, 25, and 50°C/min. The specific products were detected using a directly coupled Fourier Transform Infrared spectrometer. Results indicated that at typical geological heating rates of 3°C/Ma, significant (about 10% of the total) thermogenic carbon dioxide was released at very low temperatures (<60°C) and would be coproduced with microbiologically mediated, diagenetic carbon dioxide. At the same geological heating rate, the first 10% of thermogenic methane was determined to have been released between about 110 and 140°C while significant methane generation from the kerogen continued beyond 250°C. The absolute kinetic parameters for methane indicate that below about 60°C essentially no thermogenic methane should be expected. Thus no in situ thermogenic methane should be expected in the Mallik 2L-38 well. 1999 English 00687626 Bulletin of the Geological Survey of Canada 125-141 Geological Survey of Canada (Calgary), 3303-33 Street N.W., Calgary, Alta. T2L 2A7, Canada 544 https://www.scopus.com/inward/record.uri?eid=2-s2.0-27844609316&partnerID=40&md5=adba0d801c58bd0e57867daf9e682333 cited By 3 L.R. Snowdon article Clark1999177 Pore waters have been extracted from sediments in the permafrost interval (110-176 m) and the gas hydrate interval (886-952 m) of the JAPEX/JNOC/GSC Mallik 2L-38 drill core and analyzed for δ18O,δ2H, and geochemistry. Pore waters from the permafrost interval have δ18O values of -19.5 ± 0.5‰ (upper permafrost) and -23.1 ± 1.0‰ (lower permafrost) indicating the likely origin to be local, contemporary meteoric waters infiltrating these sediments during a period of subaerial exposure. Pore waters in the subpermafrost gas hydrate zone are isotopically depleted from seawater values, with δ18O ranging between -14‰ and -8‰c. A weak correlation between δ18O and Cl- exists in the gas-hydrate-bearing sands, consistent with the combined effect of isotopic depletion during gas hydrate formation, and enrichment associated with gas hydrate decomposition. The upper silt and deeper clayey silt sections also retain a minor correlation between isotopes and Cl-, and show strong variability in both δ18O and Cl- with depth, suggesting a history of gas hydrate formation, decomposition, and fluid migration. The Cl--δ18O relationships demonstrate that the original pore waters are a mixture of seawater with greater than 50% meteoric water. 1999 English 00687626 Bulletin of the Geological Survey of Canada 177-188 Ottawa-Carleton Geoscience Centre, Department of Earth Sciences, University of Ottawa, 140 Louis Pasteur Street, Ottawa, Ont. K1N 6N5, Canada 544 https://www.scopus.com/inward/record.uri?eid=2-s2.0-27844553844&partnerID=40&md5=3474a6f6444f4e6edd05e9abf4d257d3 cited By 0 I.D. Clark article Wright1999229 This paper summarizes laboratory determinations of the pressure-temperature (P-T) phase equilibrium conditions for methane hydrate stability in sediments recovered from the gas-hydrate-bearing interval at JAPEX/JNOC/GSC Mallik 2L-38 gas hydrate research well. Three test samples consisted of quartz-rich sand with in situ pore-water salinities of 4 ppt (parts per thousand), 20 ppt, and 40 ppt. A fourth sample was dominated by silt, with a salinity of 31 ppt. Initially, methane hydrate was regrown in the sediments, followed by the determination of P-T stability thresholds between 0°C and 12°C. Comparisons with published data for methane hydrate stability in pure gas-water systems indicate no appreciable shift in P-T stability conditions in sand with salinity of 4 ppt, but suggest a progressively increasing shift towards the higher pressure, lower temperature region for sand samples with elevated salinity. Test results for the saline silt sample indicate an additional shift in the stability threshold attributed to the effect of the porous medium in fine-grained sediments. 1999 English 00687626 Bulletin of the Geological Survey of Canada 229-240 Geological Survey of Canada, 601 Booth Street, Ottawa, Ont. K1A 0E8, Canada 544 https://www.scopus.com/inward/record.uri?eid=2-s2.0-0011601423&partnerID=40&md5=f32958f978a12aea1e07000fdd349550 cited By 29 J.F. Wright article Lorenson1999143 Molecular and isotopic composition of gases from the JAPEX/JNOC/GSC Mallik 2L-38 gas hydrate research well demonstrate that the in situ gases can be divided into three zones composed of mixtures of microbial and thermogenic gases. Sediments penetrated by the well are thermally immature; thus the sediments are probably not a source of thermogenic gas. Thermogenic gas likely migrated from depths below 5000 m. Higher concentrations of gas within and beneath the gas hydrate zone suggest that gas hydrate is a partial barrier to gas migration. Gas hydrate accumulations occur wholly within zone 3, below the base of permafrost. The gas in gas hydrate resembles, in part, the thermogenic gas in surrounding sediments and gas desorbed from lignite. Gas hydrate composition implies that the primary gas hydrate form is Structure I. However, Structure II stabilizing gases are more concentrated and isotopically partitioned in gas hydrate relative to the sediment hosting the gas hydrate, implying that Structure II gas hydrate may be present in small quantities. 1999 English 00687626 Bulletin of the Geological Survey of Canada 143-163 United States Geological Survey, MS-999, 345 Middlefield Road, Menlo Park, CA 94025, United States 544 https://www.scopus.com/inward/record.uri?eid=2-s2.0-14044272606&partnerID=40&md5=8048c0efb1458ee0465972001165626d cited By 33 T.D. Lorenson article Wright1999101 During drilling of the JAPEX/JNOC/GSC Mallik 2L-38 gas hydrate research well, core temperatures were measured immediately upon recovery in the core-logging trailer. Gas-hydrate-bearing cores were typically frozen, with temperatures as much as 6°C lower than cores containing no gas hydrate. This temperature depression is attributed to the endothermic dissociation of gas hydrate during uphole tripping, and can be used to estimate minimum in situ gas hydrate saturation. Numerical modelling of heat exchange between core and circulating mud during tripping demonstrates that cores cool to mud temperature before leaving the methane hydrate P-T stability field. Simple arguments support the hypothesis that the endothermic heat of gas hydrate dissociation is supplied largely by the release of latent heat during coincident freezing of pore waters. Assuming minimal heat exchange with circulating mud, energy-balance calculations yield estimates of the quantity of gas hydrate lost to dissociation during recovery. These estimates are comparable to the in situ gas hydrate concentrations inferred from downhole geophysical logs. 1999 English 00687626 Bulletin of the Geological Survey of Canada 101-108 Geological Survey of Canada, 601 Booth Street, Ottawa, Ont. K1A 0E8, Canada 544 https://www.scopus.com/inward/record.uri?eid=2-s2.0-0012094323&partnerID=40&md5=9db6a21346ae152cf84e6dd84a366210 cited By 8 J.F. Wright article Ohara199919 The JAPEX/JNOC/GSC Mallik 2L-38 gas hydrate research well, located in the Mackenzie Delta, Northwest Territories, Canada, was completed to 1150 m on March 30, 1998, after 39 days. Operations were undertaken through a collaborative agreement between the Japan National Oil Corporation and the Geological Survey of Canada. Research goals included evaluation of engineering technologies used to drill and core gas-hydrate-bearing strata. Eight coring runs were conducted within the permafrost interval (0-640 m) in a surface hole drilled to 687 m. Subsequently, a 340 mm surface casing was installed and the main hole was advanced to a depth of 1150 m with 16 coring runs. A cooled (∼2°C) KCl/polymer drilling mud and Drilltreat, a chemical mud additive, successfully stabilized gas hydrate within cores and formation sediments. No serious hole problems, accidents, or mishaps occurred; however, delays caused by adverse weather and mechanical problems caused cancellation of planned production testing. Coring in the main hole was successful, allowing the evaluation of four different core barrels. Gas-hydrate-bearing cores were collected in a variety of sediments between 896 and 952 m. 1999 English 00687626 Bulletin of the Geological Survey of Canada 19-30 Japan Petroleum Exploration Company, Ltd. (JAPEX), 2-2-20 Higashi-shinagawa, Shinagawa-ku, Tokyo 140-0002, Japan 544 https://www.scopus.com/inward/record.uri?eid=2-s2.0-0012094322&partnerID=40&md5=129c8db5c6299e87a7cc953b9f830580 cited By 5 T. Ohara article Uchida1999269 Core samples from the JAPEX/JNOC/GSC Mallik 2L-38 gas hydrate research well contained a variety of forms of gas hydrate within sands and granular sands in the interval from 896 to 926 m. A number of these samples were placed inside pressure vessels charged with nitrogen gas and subsequently transported to Japan for specialized dissociation experiments. X-Ray CT images were acquired, at constant intervals, from a granular sand (collected from 913.76 m) containing pore-space gas hydrate during warming from -35 to 4°C, and subsequently during stepped decreases in cell pressures (0.1 MPa) below assumed threshold stability conditions. Dissociated gas flow and sample temperatures were monitored continuously. Changes in CT values indicated that gas hydrate dissociated simultaneously, both on the exposed surfaces and within the pore spaces of the sample, in response to pressure changes. This suggested that pressure reductions were effectively transmitted through the sample, most likely because the samples were not fully saturated with gas hydrate. Gas-flow measurements indicated that a larger pressure drawdown caused a higher dissociation rate. 1999 English 00687626 Bulletin of the Geological Survey of Canada 269-279 JAPEX Research Center, Japan Petroleum Exploration Company, Ltd., 1-2-1 Hamada, Mihama-ku, Chiba 261-0025, Japan 544 https://www.scopus.com/inward/record.uri?eid=2-s2.0-0008565866&partnerID=40&md5=b6af3bc7c04c228cb2b964774dff3653 cited By 1 T. Uchida article Kurita199977 Sparse occurrences of organic-walled dinoflagellate cysts were recorded from the JAPEX/JNOC/GSC Mallik 2L-38 gas hydrate research well, Mackenzie Delta area, Northwest Territories, Canada. Some of the recorded taxa are indicative of a Paleocene-Eocene age, while others are considered to be of Cretaceous origin. Because the deepest parts of the section are correlated to the Oligocene Kugmallit Sequence, all the dinoflagellate cysts are interpreted to be reworked. According to this interpretation, the total absence of in situ marine dinoflagellate cysts suggests that the studied samples were deposited under nonmarine conditions, most likely within a fluvial system. 1999 English 00687626 Bulletin of the Geological Survey of Canada 77-80 JAPEX Research Center, Japan Petroleum Exploration Company, Ltd., 1-2-1 Hamada, Mihama-ku, Chiba 261-0025, Japan 544 Dinophyceae https://www.scopus.com/inward/record.uri?eid=2-s2.0-27844487946&partnerID=40&md5=0daa92bf1d9e828af25d221a4a0d4aff cited By 4 H. Kurita article Collett1999295 The JAPEX/JNOC/GSC Mallik 2L-38 gas hydrate research well project was designed to investigate the occurrence of in situ natural gas hydrate in the Mallik area of the Mackenzie Delta of Canada. Because gas hydrate is unstable at surface pressure and temperature conditions, a major emphasis was placed on the downhole logging program to determine the in situ physical properties of the gas-hydrate-bearing sediments. Downhole logging tool strings deployed in the Mallik 2L-38 well included the Schlumberger Platform Express with a high resolution laterolog, Array Induction Imager Tool, Dipole Shear Sonic Imager, and a Fullbore Formation Microlmager. The downhole log data obtained from the log- and core-inferred gas-hydrate-bearing sedimentary interval (897.25-1109.5 m log depth) in the Mallik 2L-38 well is depicted in a series of well displays. Also shown are numerous reservoir parameters, including gas hydrate saturation and sediment porosity log traces, calculated from available downhole well-log and core data. The gas hydrate accumulation delineated by the Mallik 2L-38 well has been determined to contain as much as 4.15109 m3 of gas in the 1 km2 area surrounding the drill site. 1999 English 00687626 Bulletin of the Geological Survey of Canada 295-311 United States Geological Survey, Denver Federal Center, MS-939, Denver, CO 80225, United States 544 https://www.scopus.com/inward/record.uri?eid=2-s2.0-27844510454&partnerID=40&md5=33b2f6f39c2a3bc8b7e99216a1656781 cited By 55 T.S. Collett article Tulk1999251 Gas hydrate samples from the JAPEX/JNOC/GSC Mallik 2L-38 gas hydrate research well were analyzed on both macroscopic and molecular scales using several complementary experimental techniques. These included gas volume analysis, thermogravimetric analysis, precision gas analysis, powder X-ray diffraction, differential scanning calorimetry, Fourier transform infrared spectroscopy, and Raman Spectroscopy. Powder X-ray diffraction indicated that the samples were Structure I gas hydrate. Enclathrated gas species were identified to be mostly methane (98-100%); however, some samples contained significant amounts of heterogeneously dispersed propane and carbon dioxide (at least 1.5-2.0%). These samples were found to be significantly more stable than samples containing methane only. In addition, Raman spectra indicate subtle variations in the cage occupancies of the mixed gas hydrate as compared to those in pure methane hydrate. 1999 English 00687626 Bulletin of the Geological Survey of Canada 251-262 Steacie Institute for Molecular Sciences, National Research Council of Canada, 100 Sussex Drive, Ottawa, Ont. K1A 0R6, Canada 544 https://www.scopus.com/inward/record.uri?eid=2-s2.0-27844433540&partnerID=40&md5=34a9c966a1c929b29edbcca47f8171e3 cited By 18 C.A. Tulk article Lee1999313 The amount of in situ gas hydrate concentrated in the sediment pore space at the JAPEX/JNOC/GSC Mallik 2L-38 gas hydrate research well was estimated by using compressional-wave (P-wave) and shear-wave (S-wave) downhole log measurements. A weighted equation developed for relating the amount of gas hydrate concentrated in the pore space of unconsolidated sediments to the increase of seismic velocities was applied to the acoustic logs with porosities derived from the formation density log. A weight of 1.56 (W=1.56) and the exponent of 1 (n=1) provided consistent estimates of gas hydrate concentration from the S-wave and the P-wave logs. Gas hydrate concentration is as much as 80% in the pore spaces, and the average gas hydrate concentration within the gas-hydrate-bearing section from 897 m to 1110 m (excluding zones where there is no gas hydrate) was calculated at 39.0% when using P-wave data and 37.8% when using S-wave data. 1999 English 00687626 Bulletin of the Geological Survey of Canada 313-322 United States Geological Survey, Denver Federal Center, MS-939, Denver, CO 80225, United States 544 https://www.scopus.com/inward/record.uri?eid=2-s2.0-0001273063&partnerID=40&md5=5e3ee895186159e800204c255a19b82a cited By 30 M.W. Lee article Miyairi1999281 Techniques for evaluating subsurface natural gas hydrate were part of the JNOC/GSC/J APEX joint research project. The physical properties of pure methane hydrate, related to well-log responses, were directly measured and/or calculated based on its physico-chemical properties. A petrophysical model of the pore-filling gas hydrate was built considering the existence of thermally dissociated free gas in the pores of the formation. Tool sensitivity to gas hydrate content was analyzed, and formation resistivity and acoustic transit time were found to show distinct sensitivity. Three practical methods for evaluating gas hydrate content were proposed and were tested to confirm their applicability: 1) the resistivity method, 2) the acoustic-velocity method, and 3) the statistical-inversion-analysis method. The porosity and gas hydrate saturation results calculated from these methods agreed quite well. Thus, reasonable interpretations can be achieved using these methods if the drilling and log measurements are carefully designed, and the zoning and parameter settings are made properly in pore-filling-type gas hydrate occurrences similar to those found in the JAPEX/JNOC/GSC Mallik 2L-38 gas hydrate research well. 1999 English 00687626 Bulletin of the Geological Survey of Canada 281-293 JAPEX Research Center, Japan Petroleum Exploration Company, Ltd., 1-2-1 Hamada, Mihama-ku, Chiba 261-0025, Japan 544 https://www.scopus.com/inward/record.uri?eid=2-s2.0-0013263687&partnerID=40&md5=ea874a8ff907e58704f90e58562b24f3 cited By 14 M. Miyairi