Linking Coupled Reservoir Modeling to Dynamic Rupture Modeling: An Automated Workflow to Simulate Induced Seismicity in Faulted Geothermal Systems

Abstract

Induced seismicity associated with subsurface fluid injection poses significant challenges for geothermal reservoir management. While quasi-static models capture long-term pressure, temperature, and stress evolution, dynamic rupture codes resolve transient earthquake mechanics. In this study, we develop a fully coupled framework that integrates both approaches to simulate fault reactivation and induced seismicity in a synthetic geothermal system. Unlike previous one-way coupled frameworks, our approach implements a closed-loop feedback, where stress redistribution from dynamically simulated seismic events is fed back into the quasi-static THM reservoir model. A 3D thermo-hydro-mechanical model tracks stress build-up during injection until a failure criterion is met, triggering a transition to a dynamic rupture solver that computes spontaneous 3D rupture propagation and seismic wave radiation. An automated coupling protocol ensures seamless data exchange between solvers. We demonstrate the framework by simulating two injection-induced events on a single-fault reservoir model. Results show that event-driven fault displacements and dynamic stress transfers significantly alter reservoir stress states. Simulated Coulomb stress changes, focal mechanisms, and slip distributions align with the ambient stress field and fault geometry. This closed-loop approach provides a robust tool for assessing seismic risk and optimizing injection strategies in geothermal environments.