Integrated Geological, Fluid Flow and Geomechanical Model of a Geothermal Field

Abstract

Geothermal reservoirs are often faulted and fractured formations. Highly conductive fractures are the main flow channels and therefore are the primary targets for well placement. During reservoir development, reinjection of cold water at high rates will not only change the stress field but could also reactivate the faults, potentially leading to seismic events. Coupling fluid flow and geomechanical simulators allows the assessment of the possible impact of productioninjection activity on the subsurface system, notably the change of flow direction and the closure and opening of fracture networks, affecting the performance of the system as a heat exchanger, and the occurrence of microseismic events due to the reactivation of faults, impacting public acceptance. This project demonstrates the construction of a coupled reservoir geomechanical model of the Rittershoffen geothermal site located in Northern Alsace (France). The simulation of the impact of future operations in terms of fracture closure and opening and microseismic events is ongoing and will be published subsequently.