Research on the THMC Coupling Model for Enhanced Geothermal Systems Based on the Framework of EDFM

Abstract

The Enhanced Geothermal System (EGS) involves a complex thermo-hydro-mechanical-chemical (THMC) coupling process during long-term heat extraction. However, many models used to solve fractured reservoir problems are computationally time-consuming, especially when dealing with reservoir-scale engineering problems. To address this challenge, this paper proposes a novel THMC coupling model that solves the governing equations using a unified FVM framework based on the embedded discrete fracture model (EDFM). The accuracy of the model is confirmed by comparing the THC coupling and displacement (M) results with the Fully Resolved Solution Method (FRSM) from MRST software and COMSOL, respectively. Moreover, the model developed is utilized to simulate and analyze the spatiotemporal behavior of pressure, temperature, concentration, and mechanical deformation in EGS. The results suggest that the model is appropriate for effectively assessing the long-term production performance of EGS.