The EGS Collab Project: Learnings from Experiment 1

Conference · Mon Feb 10 04:00:00 EST 2020

OSTI ID:1766466

Kneafsey, Timothy J. ^[1]; Blankenship, Douglas A. ^[2]; Dobson, Patrick F. ^[3]; Morris, Joe ^[4]; White, Mark D. ^[5]; Fu, Pengcheng ^[6]; Schwering, Paul C. ^[2]; Ajo-Franklin, Jonathan ^[7]; Huang, Lianjie ^[8]; Schoenball, Martin ^[3]; Johnson, Timothy C. ^[5]; Knox, Hunter A. ^[5]; Neupane, Ghanashyam ^[9]; Weers, Jon ^[10]; Horne, Roland N. ^[11]; Zhang, Yuran ^[11]; Roggenthen, Bill ^[12]; Doe, Thomas ^[13]; Mattson, Earl D. ^[9]; Valladao, Carol A. ^[3]

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1. LBNL
2. Sandia National Laboratory
3. Lawrence Berkeley National Laboratory
4. Lawrence Livermore National Lab
5. BATTELLE (PACIFIC NW LAB)
6. Lawrence Livermore National Laboratory
7. Rice University
8. Los Alamos National Laboratory
9. Idaho National Laboratory
10. IM3
11. Stanford University
12. South Dakota School of Mines & Technology
13. TDoeGeo

The primary objective of the EGS Collab Project sponsored by DOE is to increase the understanding needed to efficiently implement enhanced geothermal systems (EGS). One goal of the EGS Collab project is to create a collaborative research environment in which to study stimulation of crystalline rock at the 10 meter scale. Key to this effort is the collection of high quality data to allow comparison to numerical coupled process models in an effort to build confidence in the codes and modeling techniques used. In response to this, the EGS Collab team has created an underground test bed at the Sanford Underground Research Facility (SURF) in Lead SD at a depth of approximately 1.5 km to examine hydraulic fracturing (Experiment 1). We are currently designing a second test bed aimed at investigating shear stimulation (Experiment 2). At the Experiment 1 location, we have characterized our host rock using laboratory testing and numerous field-based geophysical and geological techniques, and created a well-instrumented test bed to allow us to carefully monitor stimulation events and flow tests. In addition to the installed geophysical sensors, we have used tracer tests, differences in the ambient microbial communities at flow collection locations, and cold water injection to inform us about dynamic flow pathways. In Experiment 1, we have hydraulically stimulated the host rock in a number times at several locations in one well, creating new fractures that connect to existing fractures between the injection and production boreholes. We have performed long-term ambient and chilled water injection tests as an analog to EGS, and have monitored system changes resulting from these water injections through geophysical monitoring, flow and pressure measurements, tracer tests, and microbiology. Here, we summarize the tests performed, issues identified including poroelastic and thermoelastic effects, Joule-Thomson effects, restarting effects, indications of flow channeling, and the primary learnings from Experiment 1.

• Research Organization: Pacific Northwest National Laboratory (PNNL), Richland, WA (United States)
• Sponsoring Organization: USDOE
• DOE Contract Number: AC05-76RL01830
• OSTI ID: 1766466
• Report Number(s): PNNL-SA-150814
• Country of Publication: United States
• Language: English

Related Subjects

Enhanced Geothermal Systems
EGS Collab
stimulation
crystalline rock
Sanford Underground Research Facility
coupled process modeling
experimental
field test
flow test