Modeling hydro-thermal processes in fractured geothermal reservoirs using embedded discrete fracture model (EDFM) and MRST

Fractures critically influence fluid flow and heat transfer in geothermal reservoirs, necessitating accurate and efficient simulation tools for resource management. Here we introduce ETH, an open-source Embedded Discrete Fracture Model (EDFM) module integrated with the MATLAB Reservoir Simulation Toolbox (MRST), enabling coupled hydrothermal simulations in both 2D and 3D fractured porous media. ETH extends prior EDFM frameworks by incorporating heat transfer and variable fluid properties, validated through four benchmarks ranging from analytical single-fracture cases to complex 3D fracture networks. Results demonstrate high accuracy (relative errors mostly <1 %) and computational efficiency, with 20–50 % reduced cost compared to FEM-based discrete fracture models. ETH’s modular design supports mesh/time convergence control and integration of additional physics, facilitating robust modeling of heterogeneous and anisotropic reservoirs. This tool advances accessible, high-fidelity simulation capabilities for geothermal reservoir characterization, development, and uncertainty quantification.