Analysis and Risk Mitigation measures for Induced Seismicity in supercriTICal gEothermal systems

ended

Combining together carbon capture and storage (CCS) and exploitation of supercritical geothermal systems (SCGS) in volcanic areas, potentially a very large clean energy resource, could open the door to a whole new cutting-edge technology and contribute to the fight against global climate change. CCS-SCGS systems are widely unexplored and constitute a very challenging problem that involves complex coupled processes of multi-phase and multi-component flow in porous media, geomechanics and seismicity. Subsurface fluid injection technologies bear an intrinsic risk of inducing earthquakes by fault re-activation. Predicting injection-induced seismicity is complicated and challenging from a numerical perspective due to the discontinuous nature of faults. ARMISTICE explores for the first time the possibility of safely combining CCS and SCGS technologies by coupling CO2 flow models, developed by the host, to the high-temperature rheology of rock and faults, developed by the ER. Current models of subsurface flow of CO2 and H2O systems are limited to water’s subcritical temperature: in WP1 we address the problem by incorporating the full-range of fluids’ equation of state to determine the optimal conditions for employing CO2 as a geothermal fluid in volcanic areas. We will achieve the objective thanks to the complementary experience of the ER on SCGS and of the host on CCS. Based on the results of flow behavior, in WP2 we will determine the potential for induced seismicity in CCS-SCGS systems and the conditions for safe exploitation. Once again, the decisive advantage to a successful implementation will rely on the complementary nature of the ER past work on fractures and discontinuity modelling, and the one of the host on fluid injection-induced seismicity. ARMISTICE will be strongly based on a career development plan backed by training on multi-phase and multi-component fluid flow, CCS and transferable skills that will make the ER a global leader in geoenergies research.