Federica Lanza, Antonio Pio Rinaldi, Luigi Passarelli, Vanille Ritz, Victor Clasen Repollés, Ryan Schultz, Federico Ciardo, Ben Dyer, Laura Ermert, Dimitrios Karvounis, Peter Meier, Arnaud Mignan, K. L. Pankow, Jim Rutledge, Joseph Moore, Luca Scarabello, Nicolas Schmid, Peidong Shi, Katinka Tuinstra, S. Wiemer
Managing induced seismicity risk is needed to enable the widespread adoption of geothermal technologies, facilitating the transition towards a decarbonized energy sector. In April 2022, real-time monitoring and forecasting of induced seismicity were tested during a three-stage hydraulic stimulation in a deep granite heat reservoir at the Utah FORGE site. Here, we analyze the recorded seismicity through statistical inference, and investigate the possible fracturing mechanisms triggered by the injection operation. Our analysis indicates that seismicity is likely induced by opening of a tensile fracture. Through pseudo-prospective forecasting, we then replay the Stage 3 stimulation and related induced seismicity as if it were happening in real-time. We demonstrate that even if the physical processes are complex and likely difficult to disentangle using seismicity alone, physics-based seismicity rate forecasting models show promise for stable forecastability of seismicity induced during hydraulic stimulation. Our results pave the way for Advanced Traffic Light Protocols (ATLP) to become standard operational technology in the mitigation strategies of deep geothermal projects.