I-Corps: Imaging and locating geothermal resources using distributed acoustic sensing deployed on telecommunication fiber cables

California Institute Of Technology, Pasadena CA

Investigators

Abstract

The broader impact/commercial potential of this I-Corps project is the development of a subsurface imaging technology that uses existing telecommunication fiber infrastructure for earthquake monitoring and subsurface imaging. The proposed technology relies on natural seismicity recorded on existing telecommunication fiber networks using a laser interferometric system called distributed acoustic sensing. This approach may significantly decrease the upfront costs of geophysical studies for geothermal energy exploration and production. Specifically, it may reduce the exploration risk through the identification of optimal subsurface structures associated with high-energy geothermal reservoirs. In addition, it also may provide invaluable insights into complex subsurface systems such as volcanoes and geothermal reservoirs. This I-Corps project is based on the development of a tomographic method that employs distributed acoustic sensing (DAS) data recorded on pre-existing telecommunication fibers. Compared to conventional seismic instruments, DAS data provides a meter-scale spatial resolution covering tens of kilometers using a single instrument. This technology has been successfully applied to a large-scale volcanic system such as the Long Valley caldera located in Mammoth Lakes, California, which significantly advanced the understanding of this volcano. Additionally, the reported subsurface images have been shown to improve the characterization of the structures associated with the hydrothermal system currently employed by a 30 MW geothermal power plant located within the caldera. This award reflects NSF's statutory mission and has been deemed worthy of support through evaluation using the Foundation's intellectual merit and broader impacts review criteria.