THMC Modeling of EGS Reservoirs -- Continuum through Discontinuum Representations. Capturing Reservoir Stimulation, Evolution and Induced Seismicity

Elsworth, Derek¹  Izadi, Ghazal¹  Gan, Quan¹  Fang, Yi¹  Taron, Josh²  Sonnenthal, Eric³ 

[1] Pennsylvania State Univ., State College, PA (United States);US Geological Survey, Menlo Park, CA (United States);Lawrence Berkeley National Lab. (LBNL), Berkeley, CA (United States)

关键词: Enhanced Geothermal Systems;    EGS;    induced seismicity;    triggered seismicity;    permeability evolution;    heat recovery;    fault reactivation;    reservoir geomechanics;    THMC;   

DOI  :  10.2172/1202233
RP-ID  :  DOE-PSU--0002761-1
PID  :  OSTI ID: 1202233

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来源: SciTech Connect

【 摘 要 】

This work has investigated the roles of effective stress induced by changes in fluid pressure, temperature and chemistry in contributing to the evolution of permeability and induced seismicity in geothermal reservoirs. This work has developed continuum models [1] to represent the progress or seismicity during both stimulation [2] and production [3]. These methods have been used to resolve anomalous observations of induced seismicity at the Newberry Volcano demonstration project [4] through the application of modeling and experimentation. Later work then focuses on the occurrence of late stage seismicity induced by thermal stresses [5] including the codifying of the timing and severity of such responses [6]. Furthermore, mechanistic linkages between observed seismicity and the evolution of permeability have been developed using data from the Newberry project [7] and benchmarked against field injection experiments. Finally, discontinuum models [8] incorporating the roles of discrete fracture networks have been applied to represent stimulation and then thermal recovery for new arrangements of geothermal wells incorporating the development of flow manifolds [9] in order to increase thermal output and longevity in EGS systems.