Seismicity characterization around the Farnsworth field site for combined large-scale CO₂ storage and EOR

Induced seismicity at levels noticeable to the public or higher is a concern for long-term, large-scale geologic carbon storage. To lower the risk of induced seismicity, it is desirable to sequester CO₂ within a region where earthquakes are rare. We characterize the natural seismicity around the Farnsworth field site for the Phase III project of the U.S. Southwest Regional Partnership on Carbon Sequestration. We study all available catalog earthquake information within a region of approximately 180km×220km (2×2 degrees) centered at the Farnsworth field. We find that there is no recorded catalog earthquake within a region of approximately 30km in radius from planned CO₂ injection well No. 13-10A. The earliest earthquake recorded within our study region occurred in 1907, and the maximum magnitude of all recorded earthquakes since then is 4.8. Out of all the earthquakes recorded in this region, only four of them have magnitudes larger than 4. Our seismicity study indicates that the seismic risk for large-scale geologic carbon storage combined with enhanced oil recovery at the Farnsworth field may be relatively low. This characterization of natural seismicity around the Farnsworth field also benefits the ongoing monitoring of induced seismicity at the site.