© ICDP, the International Continental Scientific Drilling Program, 1996-2020

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Newberry Deep Drilling Project (NDDP), Workshop Proposal

North America, U.S.A., Oregon, Bend, Newberry Volcano

new workshop-proposal: ICDP-2017/11
for the funding-period starting 2017-01-15
by Alain Bonneville, Trenton Cladouhos, Susan Petty, Adam Schultz, Carsten F. Sørli
Abstract
We propose an ICDP sponsored workshop to develop a full proposal for drilling to the ductile/brittle transition zone (T>400°C) at Newberry Volcano, central Oregon, in the Cascades volcanic arc in the US Pacific Northwest. The Newberry Geothermal Test Facility is located on the western flank of the caldera rim of Newberry Volcano. Here, hot rock is closer to the surface, making it easier to drill wells and carry out enhanced geothermal system (EGS) research. Millions of dollars have already been invested in the site for investigations above the ductile/brittle transition, resulting in a ready-to-use facility with the necessary infrastructure, environmental permits, land commitments, and monitoring plans. Several important scientific questions that would form the basis of a full drilling proposal will be addressed during this 4-day long workshop, proposed to be held in Bend, Oregon in the autumn of 2017. Most of the areas of investigation will be refined during the workshop, and additional goals are likely to be developed, but we can already mention the most important ones concern heat and mass transfer in the crust from the a fundamental point of view of natural hazards or from the point of view of geothermal energy: EGS (supercritical and beyond-brittle), volcanic hazards, mechanisms of magmatic intrusions, geomechanics close to a magmatic system, calibration of geophysical imaging techniques and drilling in a high temperature environment (> 320oC). The IDCP sponsored workshop will be led by a strong team with a balance between geothermalists, geophysicists, geologists, and volcanologists. The participants will be selected to balance academic researchers and industry. Participants will also be targeted to provide a variety of geographic specialities, balancing those familiar with the Cascades with experts who have studied other volcanic systems in the Pacific Rim and elsewhere. Expected presentations and discussion at the workshop will include: • the state of the art in drilling, coring, well testing and logging at ultra-high temperatures, • the Newberry data set collected to a depth of 3.5 km in previous well, • the Newberry geophysical data set, • results from other deep, ultra-hot wells drilled in volcanic areas, • laboratory studies of geomechanical properties of rocks at the conditions in the brittle-ductile transition, and • plans to fully fund a robust research and drilling program. The workshop organizers are open to new ideas and perspectives. We expect lively workshop discussions to lead to additional scientific objectives and refinement of the scientific objectives already identified.
Scientific Objectives
  • 1. Drilling into the brittle-ductile transition can test the efficiency of thermally induced fracturing and reservoir creation. The extent of fracturing remains a big unknown in thermally activated EGS and its knowledge and modeling are important factors for supercritical steam geothermal energy.
  • 2. Newberry Volcano has been active for ~600,000 years. The most recent eruptions in the caldera occurred 1.6 ka - 1.3 ka, and a larger event ~75 ka. A high-resolution stratigraphic column through the deepest formations of the volcano will help determine the existence of previously unreported events and determine the likelihood of their occurrence.
  • 3. Below 2000 m depth volcanic lava flows, tuffs and alluvial deposits are intruded by sills and dykes from the main magma chamber. While existing wellbores extend to ~3000 m, dykes and plutonic bodies at greater depths are inferred only from geophysical data. The characterization of these deeper formations will be an important objective of the drilling, offering a unique ground truth and verification of these interpretations.
  • 4. Knowledge of the stress regime is key to understanding of fracture generation and geometry. The workshop will consider the value of mini-frac tests, and testing new, more reliable and easily performed methods of measuring stress in geothermal wells.
  • 5. Advanced methods are required to drill and instrument very high temperature environments. The workshop will consider advanced drilling techniques, instruments and methods like high-temperature fiber-optic microseismic arrays, distributed well monitoring for production, deep borehole DC resistivity tomography electrodes, and HT gauges for ESP monitoring.
Keywords
Bend, Caldera, Geothermal, ICDP-2017/11, Magma, NDDP, Newberry, North america, Oregon, U.S.A., Volcano
Location
North America, U.S.A., Oregon, Bend, Newberry Volcano: 43.68919, -121.25489

© ICDP, the International Continental Scientific Drilling Program, 1996-2020

www.icdp-online.org