RESULTS FROM THE THE NEWBERRY VOLCANO EGS DEMONSTRATION

The Newberry Volcano EGS Demonstration in central Oregon is a 5 year DOE-funded project begun in 2010 that was designed to test recent technological advances to reduce the cost of electrical power generated by enhanced geothermal systems (EGS) in a hot (>300 C), dry well (NWG 55-29) drilled in 2008. The project started with two years of permitting, technical planning, and development of a project-specific Induced Seismicity Mitigation Plan (ISMP) to evaluate, monitor for, and mitigate felt induced seismicity.

In 2012, the well was hydraulically stimulated using water pressure below the minimum principle stress (aka hydroshearing) for 7 weeks. During the 2012 stimulation two treatments of thermally-degradable zonal isolation materials (TZIMs) successfully shifted the depth of stimulation. Injectivity changes, thermal profiles and seismicity indicate that fracture permeability in well NWG 55-29 was enhanced during the well stimulation. This proved the viability of the three significant technological developments: 1. stimulation pumps designed to run for weeks and deliver large volumes (40,000 m³) of water at moderate well-head pressure, 2. TZIMs which temporarily seal off fractures in a geothermal well to stimulate secondary and tertiary fracture zones, and 3. the geological and geophysical tools and methods used to predict the stimulation characteristics as required by the ISMP. Further analysis and field testing in 2013 determined that stimulation in 2012 did not create an economically viable reservoir in the hottest part of the well; therefore, a second stimulation has been planned for 2014. The well will be re-stimulated, applying the lessons learned from 2012. The second stimulation will employ better monitoring equipment and techniques, a more robust stimulation infrastructure and improved operational knowledge gained during the first stimulation to create a deep stimulated reservoir.