As of 10:30PM, we are currently at a depth of 3,844 ft and our directional drill team has successfully brought the hole to within 4.25 degrees from vertical. We expect further improvement throughout the night.
Because the borehole continued to deviate from vertical, a directional drilling team arrived on site earlier this evening. In the coming hours, they will perform a directional survey and bring the hole closer to vertical. Our current depth is 3,729 feet.
Although the borehole deviation held steady for a while at 3.75 degrees, the most recent survey indicated an increase in the deviation to 4.25 degrees necessitating a change of bit and addition of more stabilizers.
After the deviation of the borehole (from vertical) increased to 3.75 degrees, we tripped out of the hole at 3229 feet to replace the worn bit and top stabilizer. As of 3370 feet the borehole deviation is holding steady at 3.75 degrees.
Press conferences on the SAFOD Pilot Hole were held simultaneously in northern and southern California. Turnout and reaction to the project was quite favorable. Back at the drill site, samples continue to be collected as we near the 3000 foot mark.
Having reached stable granite at 2508 feet, we have begun casing. During casing, metal pipe is inserted into the drill hole and cement is injected around it in order to stabilize the hole for further drilling.
The current depth of the pilot hole is 2175 ft (at 7:30pm on June 19th) and drilling has slowed down following the attachment of a hard rock bit. Weathered granite is starting to show up in the cuttings.
On June 18th the bit was changed and the rate of penetration has improved dramatically from 10 ft/hr to 30 ft/hr. The first signs of crystalline rock appear to be coming across the shaker at midnight from a depth of 2100 ft.
New science team members, Jessica Murray (Stanford) and Matt d'Alessio (UC Berkeley) have arrived at the site and are enthusiastically washing cutting samples from the last 400 ft drilled.
As of today at 18:00 the SAFOD Pilot Hole is 1370 ft deep and we have not encountered any major problems and the latest deviation survey shows the hole is within 1 degree of vertical.
Now that we have reached a depth of 500' the blowout preventer can be installed, allowing the gas anlaysis system (mass spectrometer, gas chromatograph and radon detector) to be implemented.
The SAFOD Pilot Hole was spud at 7:45am on June 12th, 2002 with a 17.5 inch bit. We are now turning to the right (drilling) and expect to continue doing so for the next 45 days.
Today Naomi Boness and USGS geologist Mike Rymer covered a transect from the drill site to the San Andreas Fault assessing the local geology on the way.
