The Newberry Volcano EGS Demonstration in central Oregon, a 3 year project started in 2010, tests recent technological advances designed to reduce the cost of power generated by EGS in a hot, dry well (NWG 55-29) drilled in 2008. First, the stimulation pumps used were designed to run for weeks and deliver large volumes of water at moderate well-head pressure. Second, to stimulate multiple zones, AltaRock developed thermo-degradable zonal isolation materials (TZIMs) to seal off fractures in a geothermal well to stimulate secondary and tertiary fracture zones. The TZIMs degrade within weeks, resulting in an optimized injection/ production profile of the entire well. Third, the project followed a project-specific Induced Seismicity Mitigation Plan (ISMP) to evaluate, monitor for, and mitigate felt induced seismicity. Stimulation started October 17, 2012 and continued for 7 weeks, with over 41,000 m3 of water injected. Two TZIM treatments successfully shifted the depth of stimulation. Injectivity, DTS, and seismic analysis indicate that fracture permeability in well NWG 55-29 was enhanced by two orders of magnitude.

The Newberry Volcano EGS Demonstration in central Oregon, a 5 year project begun in 2010, tests recent technological advances designed to reduce the cost of power generated by EGS in a hot, dry well (NWG 55-29) drilled in 2008. First, the stimulation pumps used were designed to run for weeks and deliver large volumes of water at moderate well-head pressure. Second, to stimulate multiple zones, AltaRock developed thermo-degradable zonal isolation materials (TZIMs) to seal off fractures in a geothermal well to stimulate secondary and tertiary fracture zones. The TZIMs degrade within weeks, resulting in an optimized injection/ production profile of the entire well. Third, the project followed a project-specific Induced Seismicity Mitigation Plan (ISMP) to evaluate, monitor for, and mitigate felt induced seismicity. An initial stimulation was conducted in 2012 and continued for 7 weeks, with over 41,000 m3 of water injected. Further analysis indicated a shallow casing leak and an unstable formation in the open hole. The well was repaired with a shallow casing tieback and perforated liner in the open hole and re-stimulated in 2014. The second stimulation started September 23rd, 2014 and continued for 3 weeks with over 9,500 m3 of water injected. The well was treated with several batches of newly tested TZIM diverter materials and a newly designed Diverter Injection Vessel Assembly (DIVA), which was the main modification to the original injection system design used in 2012. A second round of stimulation that included two perforation shots and additional batches of TZIM was conducted on November 11th, 2014 for 9 days with an additional 4,000 m3 of water injected. The stimulations resulted in a 3-4 fold increase in injectivity, and PTS data indicates partial blocking and creation of flow zones near the bottom of the well.

The Newberry Volcano EGS Demonstration in central Oregon, a 5 year project begun in 2010, tests recent technological advances designed to reduce the cost of power generated by EGS in a hot, dry well (NWG 55-29) drilled in 2008. First, the stimulation pumps used were designed to run for weeks and deliver large volumes of water at moderate well-head pressure. Second, to stimulate multiple zones, AltaRock developed thermo-degradable zonal isolation materials (TZIMs) to seal off fractures in a geothermal well to stimulate secondary and tertiary fracture zones. The TZIMs degrade within weeks, resulting in an optimized injection/ production profile of the entire well. Third, the project followed a project-specific Induced Seismicity Mitigation Plan (ISMP) to evaluate, monitor for, and mitigate felt induced seismicity. An initial stimulation was conducted in 2012 and continued for 7 weeks, with over 41,000 m3 of water injected. Further analysis indicated a shallow casing leak and an unstable formation in the open hole. The well was repaired with a shallow casing tieback and perforated liner in the open hole and re-stimulated in 2014. The second stimulation started September 23rd, 2014 and continued for 3 weeks with over 9,500 m3 of water injected. The well was treated with several batches of newly tested TZIM diverter materials and a newly designed Diverter Injection Vessel Assembly (DIVA), which was the main modification to the original injection system design used in 2012. A second round of stimulation that included two perforation shots and additional batches of TZIM was conducted on November 11th, 2014 for 9 days with an additional 4,000 m3 of water injected. The stimulations resulted in a 3-4 fold increase in injectivity, and PTS data indicates partial blocking and creation of flow zones near the bottom of the well.

This is the first project report and induced seismicity mitigation plan for the Newberry Enhanced Geothermal Systems (EGS) Demonstration project. The primary objectives of this first phase were to obtain necessary permits and comply with all regulations, including NEPA, communicate with the public, regulators and other stakeholders, develop a geologic model by evaluating current geoscience data and characterizing existing wells, supplemented by additional injection test and wellbore survey information, and formulate a detailed stimulation plan for the following project phases. Also attached here are reports on the successive stimulation phases of the project.

Newberry Volcano, a voluminous (500 km3) basaltic/andesitic/rhyolitic shield volcano located near the intersection of the Cascade volcanic arc, the Oregon High Lava Plains and Brothers Fault Zone, and the northern Basin and Range Province, has been the site of geothermal exploration for more than 40 years. This has resulted in a unique resource: an extensive set of surficial and subsurface information appropriate to constrain the baseline structure of, and conditions within a high heat capacity magmatically hosted geothermal system. In 2012 and 2014 AltaRock Energy conducted repeated stimulation of an enhanced geothermal systems (EGS) prospect along the western flank of the Newberry Volcano. A surface based monitoring effort was conducted independent of these stimulation attempts in both 2012 and 2014 through a collaboration between NETL, Oregon State University and Zonge International. This program included utilization of 3-D and 4-D magnetotelluric, InSAR, ground-based interferometric radar, and microgravity observations within and surrounding the planned EGS stimulation zone. These observations as well as borehole and microseismic stress field and location solutions provided by AltaRock and its collaborators, in combination with well logs, petrologic and geochemical data sets, LIDAR mapping of fault traces and extrusive volcanics, surficial geologic mapping and seismic tomography, have resulted in development of a framework, subsurface geologic model for Newberry Volcano. The Newberry subsurface geologic model is a three-dimensional digital model constructed in EarthVision that enables lithology, directly and remotely measured material properties, and derived properties such as permeability, porosity and temperature, to be coregistered. This provides a powerful tool for characterizing and evaluating the sustainability of the site for EGS production and testing, particularly within the data-dense western portion of the volcano. The model has implications for understanding the previous EGS stimulations at Newberry as well as supporting future research and resource characterization opportunities. A portion of the Newberry area has been selected as a candidate site for the DOE FORGE (Frontier Observatory for Research in Geothermal Energy) Program through a collaboration between Pacific Northwest National Laboratory, Oregon State University, AltaRock Energy and additional partners. Thus, the conceptual geologic model presented here will support and benefit from future enhancements associated with that effort. --Mark-Moser et al. 2016

Newberry Volcano, a voluminous (500 km3) basaltic/andesitic/rhyolitic shield volcano located near the intersection of the Cascade volcanic arc, the Oregon High Lava Plains and Brothers Fault Zone, and the northern Basin and Range Province, has been the site of geothermal exploration for more than 40 years. This has resulted in a unique resource: an extensive set of surficial and subsurface information appropriate to constrain the baseline structure of, and conditions within a high heat capacity magmatically hosted geothermal system. In 2012 and 2014 AltaRock Energy conducted repeated stimulation of an enhanced geothermal systems (EGS) prospect along the western flank of the Newberry Volcano. A surface based monitoring effort was conducted independent of these stimulation attempts in both 2012 and 2014 through a collaboration between NETL, Oregon State University and Zonge International. This program included utilization of 3-D and 4-D magnetotelluric, InSAR, ground-based interferometric radar, and microgravity observations within and surrounding the planned EGS stimulation zone. These observations as well as borehole and microseismic stress field and location solutions provided by AltaRock and its collaborators, in combination with well logs, petrologic and geochemical data sets, LIDAR mapping of fault traces and extrusive volcanics, surficial geologic mapping and seismic tomography, have resulted in development of a framework, subsurface geologic model for Newberry Volcano. The Newberry subsurface geologic model is a three-dimensional digital model constructed in EarthVision that enables lithology, directly and remotely measured material properties, and derived properties such as permeability, porosity and temperature, to be coregistered. This provides a powerful tool for characterizing and evaluating the sustainability of the site for EGS production and testing, particularly within the data-dense western portion of the volcano. The model has implications for understanding the previous EGS stimulations at Newberry as well as supporting future research and resource characterization opportunities. A portion of the Newberry area has been selected as a candidate site for the DOE FORGE (Frontier Observatory for Research in Geothermal Energy) Program through a collaboration between Pacific Northwest National Laboratory, Oregon State University, AltaRock Energy and additional partners. Thus, the conceptual geologic model presented here will support and benefit from future enhancements associated with that effort. --Mark-Moser et al. 2016

As part of the planning for stimulation of the Newberry Volcano Enhanced Geothermal Systems (EGS) Demonstration project in Oregon, a high-resolution borehole televiewer (BHTV) log was acquired using the ALT ABI85 BHTV tool in the slightly deviated NWG 55-29 well. The image log reveals an extensive network of fractures in a conjugate set striking approximately N-S and dipping 50 deg that are well oriented for normal slip and are consistent with surface-breaking regional normal faults in the vicinity. Similarly, breakouts indicate a consistent minimum horizontal stress, Shmin, azimuth of 092.3 +/- 17.3 deg. In conjunction with a suite of geophysical logs, a model of the stress magnitudes constrained by the width of breakouts at depth and a model of rock strength independently indicates a predominantly normal faulting stress regime.

Final results of a 3D finite difference thermal model of Newberry Volcano, Oregon. Model data are formatted as a text file with four data columns (X, Y, Z, T). X and Y coordinates are in UTM (NAD83 Zone 10N), Z is elevation from mean sea level (meters), T is temperature in deg C. Model is 40km X 40km X 12.5 km, grid node spacing is 100m in X, Y, and Z directions. A symmetric cylinder shaped magmatic heat source centered on the present day caldera is the modeled heat source. The center of the modeled body is a -1700 m (elevation) and is 600m thick with a radius of 8700m. This is the best fit results from 2D modeling of the west flank of the volcano. The model accounts for temperature dependent thermal properties and latent heat of crystallization. For additional details, assumptions made, data used, and a discussion of the validity of the model see Frone, 2015 (Link below).

Final results of a 3D finite difference thermal model of Newberry Volcano, Oregon. Model data are formatted as a text file with four data columns (X, Y, Z, T). X and Y coordinates are in UTM (NAD83 Zone 10N), Z is elevation from mean sea level (meters), T is temperature in deg C. Model is 40km X 40km X 12.5 km, grid node spacing is 100m in X, Y, and Z directions. A symmetric cylinder shaped magmatic heat source centered on the present day caldera is the modeled heat source. The center of the modeled body is a -1700 m (elevation) and is 600m thick with a radius of 8700m. This is the best fit results from 2D modeling of the west flank of the volcano. The model accounts for temperature dependent thermal properties and latent heat of crystallization. For additional details, assumptions made, data used, and a discussion of the validity of the model see Frone, 2015 (Link below).

The proposed Newberry Volcano FORGE site is in central Oregon on the northwest flank of the largest volcano in the Cascades volcanic arc. Beneath Newberry Volcano is one of the largest geothermal heat reservoirs in the western United States, extensively studied for the last 40 years. The large, shallow (200 deg C at less than 2 km depth), conductive thermal anomaly has already been well characterized by extensive drilling and geophysical surveys. Four deep (greater than 3,000 m) boreholes completed on the leasehold currently managed by AltaRock have conductive thermal gradients with bottom hole temperatures above 320 deg C. Three large geothermal pads and two deep geothermal wells exist on the leasehold as well as eight, 200-290 m deep monitoring boreholes that have been used for seismic monitoring and sampling of shallow groundwater. All these investments have built the scientific foundation that establishes the site as high EGS potential, demonstrates a record of addressing potential risks (induced seismicity, wildlife, groundwater, etc.), and has developed true support and engagement with the local and regional communities. The high temperatures at relatively shallow depths at the site will allow a greater variety of drilling methods to be tested and a greater share of funds to be reserved for non-drilling activities.