The test featured the SIMFIP (Step-Rate Injection Method for Fracture In-Situ Properties), a tool that revolutionizes the way scientists can study geothermal energy, a process that pulls heat from the earth as it extracts steam or hot water, which is then converted to electricity.
Developed at Lawrence Berkeley National Laboratory (LBNL), the SIMFIP allows precise measurements of displacements in the rock and, most importantly, the aperture, or opening, of a hydro fracture.
The SIMFIP measures fracture openings in hard rock in the EGS Collab test site at Homestake Mine in South Dakota. The team had drilled eight slightly downward-sloping boreholes in the rib (side) of the West Drift: The injection hole, used for stimulating the rock, and production well, which produces the fluid, run parallel to each other through the rock. Six other boreholes contain equipment to monitor microseismic activity (rock displacement); electrical resistivity tomography (subsurface imaging); temperature; and strain (how rocks move when stimulated).
