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Abstract We investigate the relative importance of injection and production on the spatial‐temporal distribution of induced seismicity at the Raft River geothermal field. We use time‐series of InSAR measurements to document surface deformation and calibrate a hydro‐mechanical model to estimate effective stress changes imparted by injection and production. Seismicity, located predominantly in the basement, is induced primarily by poroelastic stresses from cold water reinjection into a shallower reservoir. The poroelastic effect of production from a deeper reservoir is minimal and inconsistent with observed seismicity, as is pore‐pressure‐diffusion in the basement and along reactivated faults. We estimate an initial strength excess of ∼20 kPa in the basement and sedimentary cover, but the seismicity rate in the sedimentary cover is four times lower, reflecting lower density of seed‐points for earthquake nucleation. Our modeling workflow could be used to assess the impact of fluid extraction or injection on seismicity and help design or guide operations.
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Investigating the role of thermal stresses on induced seismicity
We investigate the influence of thermal stresses on induced seismicity in the context of geothermal energy production at Brawley and Coso in California. We resort to thermo-hydro-mechanical modeling and used measurements of surface deformation to validate our simulations. We find that thermal stresses induced by fluid injections for geothermal energy production play an important role in either triggering or impeding seismicity. We speculate that thermal stresses may also play an important role in inducing fracturing and seismicity in other context of fluid injection for CO2 storage, disposal of wastewater or unconventional oil and gas production for example
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- Award ID(s):
- 1822214
- PAR ID:
- 10226188
- Date Published:
- Journal Name:
- SEG Technical Program Expanded Abstracts 2020
- Page Range / eLocation ID:
- 1335 to 1338
- Format(s):
- Medium: X
- Sponsoring Org:
- National Science Foundation
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- Free Publicly Accessible Full Text
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Accepted Manuscript1.0
- Conference Paper:
- https://doi.org/10.1190/segam2020-3423979.1
