SEISMICITY STUDY AT THE FIELD SITE OF THE SAN JUAN BASIN CARBONSAFE PHASE III PROJECT

Assessing seismic hazards and mapping subsurface fault structures are crucial for safe and successful CO2 injection and storage. The recorded background seismicity is very sparse at the field site of the planned San Juan Basin CarbonSAFE Phase III project, which is located close to the city of Farmington in northwest New Mexico. Because there is only one permanent broadband station operating within 100 km of the field site, the true rate of background seismicity is unknown. To better evaluate the seismic risk hazards for CO2 injection, we deployed 16 geophones and 3 broadband seismic sensors in January/February 2022 to monitor the background seismicity. The sensors cover an area of approximately 40 x 20 km². We processed the recorded seismicity waveform data using both conventional methods and machine learning methods to detect and locate microseismic events. Preliminary results show a detection of at least 70 events with magnitudes ranging from 0 to 2.0 during a period of four months. The event locations form a few NE-SW trends. Further analysis of the recorded events with more precise locations will help better delineate the subsurface fault structures and assess the potential seismic hazards.