Numerical Simulation of the Circulation Tests in 2024 at the Utah FORGE Site

ABSTRACT: This study presents numerical simulations of the August-September 2024 circulation test conducted at the Utah FORGE site, an Enhanced Geothermal System (EGS) project. The one-month circulation test followed a hydraulic stimulation campaign, aiming to assess fluid flow and heat transfer within the fractured reservoir. The circulation test was performed between an injection and a production well, with flow pathways identified using fiber optic sensing, microseismicity, and spinner test data. The numerical simulations were conducted using XSiteTM, a Thermal-Hydro-Mechanical (THM) modeling tool, to history match field observations. The model incorporated key reservoir characteristics, including fracture geometry, aperture sizes, and flow distributions derived from test data. Simulation results closely aligned with field data, capturing temperature trends, though minor discrepancies were noted due to natural fracture complexities. This work contributes to improved predictive capabilities for EGS performance and provides insights into optimizing geothermal resource development.