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DOE OSTI · 3028321

Final Report for Closing the Loop Between In Situ Stress Complexity and EGS Fracture Complexity

Fei, Frank [Lawrence Livermore National Laboratory (LLNL), Livermore, CA (United States)]·Kroll, Kayla [Lawrence Livermore National Laboratory (LLNL), Livermore, CA (United States)]·Wang, Chaoyi [Lawrence Livermore National Laboratory (LLNL), Livermore, CA (United States)]·Cusini, Matteo [Lawrence Livermore National Laboratory (LLNL), Livermore, CA (United States)]·Bunger, Andrew [Univ. of Pittsburgh, PA (United States)]·Lu, Yunxing [Univ. of Pittsburgh, PA (United States)]
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Abstract

Characterizing in situ stress is essential in Enhanced Geothermal System (EGS) for both risk assessment and operation design. Standard stress measurement techniques such as diagnostic fracture injection tests (DFITs) require creating hydraulic fractures and apply analytical methods such as the G -function analysis to estimate the stress. These classical approaches rely on several assumptions, including but not limited to: (i) the induced fracture is planar and persistent, and (ii) the fracture plane is normal to the minimum horizontal stress. However, these assumptions may not hold in EGS environments like Utah FORGE, where thermo-hydro-mechanical (THM) coupling, wellbore deviation, and rock heterogeneity can alter the local stress condition and consequently lead to fracture complexities in both near-well and far-field regions.

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Fei, Frank [Lawrence Livermore National Laboratory (LLNL), Livermore, CA (United States)], Kroll, Kayla [Lawrence Livermore National Laboratory (LLNL), Livermore, CA (United States)], Wang, Chaoyi [Lawrence Livermore National Laboratory (LLNL), Livermore, CA (United States)], Cusini, Matteo [Lawrence Livermore National Laboratory (LLNL), Livermore, CA (United States)], Bunger, Andrew [Univ. of Pittsburgh, PA (United States)], Lu, Yunxing [Univ. of Pittsburgh, PA (United States)]. 2026-04-09. Final Report for Closing the Loop Between In Situ Stress Complexity and EGS Fracture Complexity. https://doi.org/10.2172/3028321

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