Thermo-Hydraulic Modeling of Long-Term Circulation Tests at the Utah FORGE Site

Abstract

The Utah Frontier Observatory for Research in Geothermal Energy (FORGE) site recently conducted a successful 30-day commercial-scale circulation test between wells 16A and 16B. Prior to the test, stimulation and propping of the discrete fracture network (DFN) connecting these wells were performed. Based on the seismic data collected from the stimulation, an updated DFN was developed. In this study, the updated DFN served as the foundation for our thermo-hydraulic (TH) modeling of the April and August 2024 circulation tests using the FALCON (Fracturing And Liquid CONvection) code. The porosity and permeability in the hydraulic model were adjusted to incorporate the DFN. Fluid temperature, pressure, and flow rates from the circulation tests were compared to the TH simulation results. The DFN extent and zonal flow were modified to achieve a better fit between the experimental and simulation data. The refined model was then used to conduct long-term circulation simulations over a period of one year to evaluate the thermal performance of the system.