The EGS Collab Project sponsored by DOE is comprised of eight national laboratories, six universities, and industrial partners who are working to improve geothermal technologies. Our primary objective is to increase the understanding needed to efficiently implement enhanced geothermal systems (EGS) through creating a collaborative research environment in which to study simulation of crystalline rock at the 10 meter scale. The project focus is to test and verify computational models that can be used in EGS or the Frontier Observatory for Research in Geothermal Energy (FORGE) EGS field laboratory. Key to this effort is the collection of high quality data during stimulation and flow tests to allow comparison to numerical coupled process models in an effort to build confidence in the codes and modeling techniques used. In response to this research need, the EGS Collab team has created an underground test bed at the Sanford Underground Research Facility (SURF) in Lead, SD at a depth of approximately 1.5 km to examine hydraulic fracturing (Experiment 1). We are currently designing a second test bed aimed at investigating shear stimulation (Experiment 2).
Our field experiments are extensively monitored using continuous active source seismic monitoring (CASSM), distributed temperature (DTS) and strain (DSS), acoustic emissions (AE), passive seismic, and electrical resistance tomography (ERT) in a well-characterized test bed. In addition, we are using Step-Rate Injection Method for Fracture In-Situ Properties (SIMFIP) tools in our active boreholes to directly measure fracture opening and shear.