Newberry EGS Demonstration: Phase 2.2 Report

Cladouhos, Trenton T.; Petty, Susan; Swyer, Mike; Yahaya, Nordin; Garrison, Geoff; Uddenberg, Matt; Grasso, Kyla; Stern, Paul; Sonnenthal, Eric; Foulger, G. R.; Julian, Bruce R.

doi:10.2172/1214834

Cited by 6 publications

(13 citation statements)

References 0 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…A similar type of faulting was observed from breakouts at the Newberry NWG-55-29 borehole utilizing a high temperature borehole televiewer before the stimulations (Davatzes and Hickman, 2011). These studies implied that the stress regime at Newberry is similar to the regional stresses and injection planning was based on these observations (Cladouhos et al, 2015). Further analysis of moment tensors for the 2014 stimulation suggested that, as a whole, the local stress field at the time of the stimulation was not consistent with the regional stress regime, and Cladouhos et al (2015) speculate that the stress field at the bottom of the well might be dependent on other factors, such as the location of the Newberry magma chamber.…”

Section: Introductionmentioning

confidence: 77%

“…These studies implied that the stress regime at Newberry is similar to the regional stresses and injection planning was based on these observations (Cladouhos et al, 2015). Further analysis of moment tensors for the 2014 stimulation suggested that, as a whole, the local stress field at the time of the stimulation was not consistent with the regional stress regime, and Cladouhos et al (2015) speculate that the stress field at the bottom of the well might be dependent on other factors, such as the location of the Newberry magma chamber. Even thought the size of the magma chamber is not well constrained, calculations for different depths suggest that stress due to the magma chamber might be substantial, with a horizontal E-W compression as the strongest stress (Cladouhos et al, 2015).…”

Section: Introductionmentioning

confidence: 77%

“…Moment tensor solutions for events associated with the 2012 and 2014 Newberry stimulations were determined using first motion polarities and amplitude ratios (Foulger and Julian, 2013;Cladouhos et al, 2015). Results showed a wide range in focal-plane strike and a large number of moment tensor solutions with significant non-double couple components.…”

Section: Introductionmentioning

confidence: 99%

“…Reported non-double couple moment tensors were particularly prominent for the small, predominantly Mw<1.3, shallower events associated with the 2014 stimulation. Cladouhos et al (2015) suggested that these small events indicate crack-opening (Cladouhos et al, 2015).…”

Section: Introductionmentioning

confidence: 99%

See 3 more Smart Citations

Microseismic Focal Mechanisms and Implications for Changes in Stress during the 2014 Newberry EGS Stimulation

Aguiar

Myers

2019

Bulletin of the Seismological Society of America

View full text Add to dashboard Cite

We adapt the relative polarity method from Shelly et al. (2016) to compute focal mechanisms for microearthquakes associated with the 2014 hydroshearing stimulation at the Newberry volcano geothermal site. We focus the analysis on events relocated by Aguiar and Myers (2018), who report that six event clusters predominantly comprise the 2014 sequence. Data quality allows focal mechanism analysis for four of the six event clusters. We use Hardebeck and Shearer (2002, 2003; hereafter HASH) to compute focal mechanisms based on first‐motion polarities and S/P amplitude ratios. We manually determine P‐ and S‐wave polarities for a well‐recorded reference event in each cluster, then use waveform cross correlation to determine whether recordings of other events in the cluster are the same or reversed polarity at each network station. Most waveform polarities are consistent with the affiliated reference event, indicating similar focal mechanisms within each cluster. The deeper clusters are east–west‐striking normal faults, whereas the shallower clusters, close to the top of the open‐hole section of the borehole, are strike slip with east–west motion. Regional studies and prestimulation borehole breakouts find the maximum stress direction is vertical and maximum horizontal stress is approximately north–south. Fault geometry and focal mechanisms of microseismicity during the stimulation suggest that increased pressure from fluid injection predominantly caused changes in horizontal stress, consistent with predictions from numerical studies of stress change caused by fluid injection. At shallow depths, where previous studies suggest the difference between vertical and horizontal stress is lowest, injection appears to have rotated the direction of maximum stress from vertical to horizontal, resulting in strike‐slip motion. At greater depth, vertical stress continued to be the dominant direction during the stimulation, but fault orientation indicates either reactivation of pre‐existing fractures or rotation of the direction of maximum horizontal stress from approximately north–south to east–west.

show abstract

Section: Introductionmentioning

confidence: 77%

Section: Introductionmentioning

confidence: 77%

Section: Introductionmentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

See 2 more Smart Citations

Microseismic Focal Mechanisms and Implications for Changes in Stress during the 2014 Newberry EGS Stimulation

Aguiar

Myers

2019

Bulletin of the Seismological Society of America

View full text Add to dashboard Cite

show abstract

“…In addition to the geothermal conditions appropriate for conventional and super-critical EGS, the prospect of geothermal energy research and development at the Newberry Deep Drilling Project (NDDP) site has the strong support of all the local communities eager for the economic boost that geothermal energy would bring to the area. That support has arisen through many years of public outreach and engagement during the Newberry EGS demonstration and monitoring projects (Cladouhos et al, 2012) that preceded the ICDP workshop at the OSU-Cascades campus in Bend.…”

Section: Geothermalmentioning

confidence: 99%

The Newberry Deep Drilling Project (NDDP) workshop

et al. 2018

Self Cite

View full text Add to dashboard Cite

Abstract. The important scientific questions that will form the basis of a full proposal to drill a deep well to the ductile–brittle transition zone (T>400 ∘C) at Newberry Volcano, central Oregon state, USA, were discussed during an International Continental Drilling Program (ICDP) sponsored workshop held at the Oregon State University-Cascades campus in Bend, Oregon, from 10 to 13 September 2017. Newberry Volcano is one of the largest geothermal heat reservoirs in the USA and has been extensively studied for the last 40 years. The Newberry Deep Drilling Project (NDDP) will be located at an idle geothermal exploration well, NWG 46-16, drilled in 2008, 3500 m deep and 340–374 ∘C at bottom, which will be deepened another 1000 to 1300 m to reach 500 ∘C. The workshop concluded by setting ambitious goals for the NDDP: (1) test the enhanced geothermal system (EGS) above the critical point of water, (2) collect samples of rocks within the brittle–ductile transition, (3) investigate volcanic hazards, (4) study magmatic geomechanics, (5) calibrate geophysical imaging techniques, and (6) test technology for drilling, well completion, and geophysical monitoring in a very high-temperature environment. Based on these recommendations, a full drilling proposal was submitted in January 2018 to the ICDP for deepening an existing well. The next steps will be to continue building a team with project, technology, and investment partners to make the NDDP a reality.

show abstract