Nevada Play Fairway project: Phase 3

GBCGE project personnel: Dr. James Faulds (PI); Nicholas Hinz; Dr. Mark Coolbaugh; Dr. Bridget Ayling; Steve DeOreo; Jason Craig.

Project collaborators: United States Geological Survey; Energy & Geoscience Institute at the University of Utah

Project duration: 24 months: 1 October 2017 – 30 September 2019.

Funding agency: U.S. Department of Energy Geothermal Technologies Office (award number DE-EE0006731).

Total project funding: Phase 3: $1,500,000

Project goals and accomplishments: This project aimed to validate the geothermal play fairway workflow developed in Phases 1 and 2 via confirmation (thermal gradient) drilling and more detailed geophysical surveys. The geothermal play fairway methodology involves integration of multiple geologic, geophysical, and geochemical parameters, utilizing quantitative geostatistical analyses, to assess geothermal potential. Two locations for possible blind geothermal systems (i.e., no surface hot springs or steam vents) were prioritized for Phase 3 work: 1) southeastern Gabbs Valley in Mineral County, and 2) northern Granite Springs Valley in Pershing County. At these sites, project tasks included:

  1. Drilling TG holes to define the size of the thermal anomaly and identify possible up-flow zones.
  2. Collecting and analyze new fluid samples directly associated with each resource to better define the reservoir temperature and provide direct context for the TG results.
  3. Collecting more detailed potential field geophysics (gravity and magnetics) for building detailed 3D geologic models of each structural target area.
  4. Integrating potential field geophysics with existing Phase II data and new drill data to build or update existing 3D geologic models.
  5. Collecting MT data to use with the 3D geologic model and temperature data to help build conceptual models of each reservoir and provide a clear road map for targeting deep geothermal wells by industry.
  6. Integrating all data to develop conceptual models of the geothermal resources, identify and rank deep drilling targets, provide estimates of resource size, and present the Phase III results in context of the play fairway analysis.

GeoProbe drilling was conducted at Granite Springs Valley in 2018, and thermal gradient drilling was conducted at both sites in 2018 and 2019. The drilling identified two new blind geothermal systems. At Gabbs Valley, maximum temperatures of 125°C at ~152 m depth were encountered, and at Granite Springs Valley, a maximum temperature of 96°C at 250 m was encountered (Faulds et al., 2018, 2019).

Photo of drilling a shallow geothermal exploration well during Phase 3 of the NV play fairway project in south-eastern Gabbs Valley, Nevada
Drilling a shallow geothermal exploration well during Phase 3 of the NV play fairway project in south-eastern Gabbs Valley, Nevada.
Map showing the location of the Geoprobe and thermal gradient holes drilled in Granite Springs Valley for the NV Play Fairway project
Location of the shallow GeoProbe and thermal gradient holes that were drilled in Granite Springs Valley, Nevada during Phase 3 of the NV play fairway project

Project publications (listed chronologically):

  • Media release: Nevada Today, August 2017
  • Earney, T.E., Schermerhorn, W.D., Glen, J.M., Peacock, J., Craig, J.W., Faulds, J.E., Hinz, N.H., Siler, D., (2018) Geophysical Investigations of a Blind Geothermal System in Southern Gabbs Valley, Nevada. Geothermal Resources Council Transactions, Vol. 42. https://www.geothermal-library.org/index.php?mode=pubs&action=view&record=1033936
  • Faulds, J.E., Craig, J.W., Hinz, N.H., Coolbaugh, M.F., Glen, J.M., Earney, T.E., Schermerhorn, W.D., Peacock, J., DeOreo, S., Siler, D.L., (2018). Discovery of a Blind Geothermal System in Southern Gabbs Valley, Western Nevada, through Application of the Play Fairway Analysis at Multiple Scales. Geothermal Resources Council Transactions, Vol. 42. https://www.geothermal-library.org/index.php?mode=pubs&action=view&record=1033921
  • Faulds, J.E., Hinz, N.H., Coolbaugh, Ramelli, A., M.F., Glen, J.M., Ayling, B.F., Wannamaker, P.E., DeOreo, S., Siler, D.L., Craig, J.W., (2019). Vectoring into Potential Blind Geothermal Systems in the Granite Springs Valley Area, Western Nevada: Application of the Play Fairway Analysis at Multiple Scales at Multiple Scales. Proceedings of the 44th Workshop on Geothermal Reservoir Engineering, Stanford University, February 11-13th, 2019. SGP-TR-214. https://pangea.stanford.edu/ERE/db/GeoConf/papers/SGW/2020/Faulds.pdf 
  • Siler, D., Witter, J., Craig, J., Faulds, J., Glen, J., Earney, T., Schermerhorn, W., Peacock, J., Fournier, D., Nevada Play-Fairway Team (2020). Using 3D gravity inversion modeling to iteratively refine 3D geologic maps: The Nevada Play-fairway project, Southern Gabbs Valley, Nevada. Transactions, Geothermal Resources Council annual meeting, October 19-23, 2020, Vol. 44. https://www.geothermal-library.org/index.php?mode=pubs&action=view&record=1034243
  • Faulds, J. E., Hinz, N. H., Coolbaugh, M. F., McConville, E., Craig, J., Ayling, B. F., Glen, J., Sadowski, A., Siler, D., DeOreo, S., (2021). The Nevada Geothermal Play Fairway Project: Exploring for Blind Geothermal Systems Through Integrated Geological, Geochemical, and Geophysical Analyses. Proceedings, World Geothermal Congress, Reykjavik, Iceland.
  • Craig, J. W., Faulds, J.E., Hinz, N.H., Earney, T.E., Schermerhorn, W.D., Siler, D.L.,  Glen, J.M., Peacock, J., Coolbaugh, M.F., DeOreo, S.B., (2021), Discovery and analysis of a blind geothermal system in southeastern Gabbs Valley, western Nevada, USA. Geothermics, Vol. 97.  https://doi.org/10.1016/j.geothermics.2021.102177 

 

 

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