Fracture Characterization Revealed by Microseismicity at Cape Modern Geothermal Field, Utah

Abstract

Microseismicity during stimulation and production related to enhanced geothermal systems (EGS) contains rich information of reservoirs including fracture locations, its orientations, fluid migration, and permeability. The Cape Modern Geothermal Field has been monitored by seismic instrument including shallow-borehole seismometers, surface nodal arrays with and without data telemetry, and borehole distributed acoustic sensing (DAS). We apply comprehensive artificial-intelligence (AI)-aided analysis of seismicity for detection, location, focal mechanisms, and stress characterization to understand the evolution of seismicity and reservoir changes. Multiple fractures are revealed by the location and focal mechanisms of small events. We also compare the quality of datasets recorded by different instrument to make a recommendation of optimal network for seismic monitoring.