Enhanced Geothermal System Design Using GeoDT and Fracture Caging — EGS Collab Stimulation Prediction Study

Enhanced Geothermal System (EGS) design optimization requires simultaneous evaluation of well placement, well stimulation, flow rates, pumping pressures, seismic stability, and power production. Furthermore, it is crucial to consider subsurface uncertainty to evaluate the probability of success of various design options to inform good decision making. In this study, we present our analysis of various injection flow rates and volumes for fracture hydraulic stimulation and fluid circulation through the EGS Collab Project’s Experiment 2 & 3 test bed at Sanford Underground Research Facility (SURF) in South Dakota. Here, our goal is to identify the minimum, optimum, and maximum injection parameters that should ensure successful well stimulation and observation of produced fluid cooling (i.e., thermal breakthrough) within a targeted timeframe of 24 hours to 6 months. This work uses our Geothermal Design Tool (GeoDT). Based on this analysis, we predict that fracture caging (i.e., containment of a fluid pressure propped fracture) will be both possible and necessary for successful well stimulation and observing thermal breakthrough.