AltaRock Energy Inc., the Sausalito, Calif.-based firm trying to tap into geothermal energy by creating rock fissures in Geysers Geothermal Field in Lake County, Calif., suspended operations on Sept. 2 because of “physical difficulties” encountered when drilling the first 12,000-ft well. The project, funded by $6 million in federal funding along with private money, was controversial because of the possibility that the rock-drilling would trigger earthquakes. The engineered fissures are created by using a hydraulic pressure of up to 4,000 psi to “hydroshear” existing fractures, causing them to open slightly and slip.
Controversial Geothermal Job Suspended for Drilling Problems
September 9, 2009