Department of Energy

The purpose of the project is to develop and test an EGS reservoir using an existing 10,060 foot geothermal well. The reservoir will be created using a process called hydroshearing, in which cold water is injected through the well and into existing fractures of hot rock at depths between 6,500 and 10,060 feet. Once an enhanced geothermal reservoir is created, AltaRock will drill two production wells in to the newly created/enhanced geothermal reservoir. The cold water slightly expands and extends the fractures creating additional surface area where water can circulate through hot rocks and heat up, much like the heat exchange process of a radiator. Shallow groundwater wells will provide cold water for the project. The hydroshearing process will produce microseismic events. An array of sensitive seismometers will be installed on the surface and in bore-holes for real-time monitoring. While these microseismic events may have the potential to be felt in nearby communities like La Pine, engineering evaluations determined the seismicity had a very low risk of being felt by people in the vicinity of the project and an even lower risk that any damaging seismic events could occur. In addition, an Induced Seismicity Mitigation Plan has been developed which will take proactive measures to prevent microseismicity. The project is located approximately 22 miles south of Bend in the Deschutes National Forest along the western flank of the Newberry Volcano. With the exception of one strong motion sensor and one seismic monitoring station, the project is located outside the Newberry National Volcanic Monument. Although the project is located entirely within the Deschutes National Forest, the BLM is the lead agency as it has jurisdiction over geothermal leases on Federal lands. In addition, the U.S. Department of Energy is funding a portion of the project through the American Reinvestment and Recovery Act. The Forest Service and Department of Energy are cooperating agencies for this project.