Overview and Preliminary Results of the Project SEE4GEO: Seismoelectric Effects for Geothermal Resources Assessment and Monitoring

Geothermal power plant operations circulate large amounts of fluid through the subsurface. During the exploration phase, we typically have poor understanding of subsurface fluid transportation dynamics at reservoir depths. Being able to identify pre-existing water-filled fracture networks greatly helps to assess geothermal resources and targets, and inform on and monitor stimulation successes and risk mitigation, by mapping newly activated fracture networks. Monitoring of geothermal resources rely predominantly on seismic techniques, which alone do not capture fluid-phase properties. On the other hand, electromagnetic (EM) measurements add constraints to the fluid-phase properties, such as resistivity and permeability, but with little sensitivity to the rock structure. Here we are introducing the use of seismoelectric effects (SEE), which arise from seismic-to-electromagnetic conversion in naturally charged porous media with a certain degree of fluid saturation. The SEE technique provides the benefits of both EM and seismic technologies, with estimated field survey costs that are similar to data acquisition of only a single data type, keeping operations affordable. This project relies on a fully integrated approach to assess the potential of SEE for the exploration and development of geothermal systems, based on numerical simulations, and experimental and field analysis. In this contribution, we will show preliminary results on SEE numerical modeling and experimental setup, as well as present an overview of the upcoming field deployments. This project has been subsidized through the Cofund GEOTHERMICA by the U.S. Department of Energy, Office of Energy Efficiency and Renewable Energy, under Contract DE-AC52-07NA27344 with Lawrence Livermore National Laboratory, by the French Environment and Energy Management Agency, and by the Research Council of Norway.