Compact Phased Arrays for Microseismic Monitoring

Abstract

A network of four SADAR® arrays installed at Carbon Management Canada’s (CMC) Containment and Monitoring Institute (CaMI) Field Research Station provides an example of the results achievable through passive monitoring of microseismicity at an active CO2 storage facility. The SADAR arrays, designed as compact volumetric phased arrays, provide a passive, persistent, and permanent data acquisition and analysis capability. Data from compact phased arrays are processed to take advantage of the spatial coherence of the incident seismic signals to increase signal resolution while suppressing noise and clutter signals, and simultaneously providing signal attributes such as angle-of-incidence and phase velocity. The network of arrays allows for automation of location and magnitude determination at a reduced channel count and sensor footprint. We present results from a nine-day reporting period, a subset of the overall compiled seismic event bulletin, chosen because the time span contains both CO2 injection events as well as other non-injection activities. A total of 55 events were detected and located with an Mw = -2.5 threshold. The results demonstrate the promising performance of permanently deployed, networked SADAR arrays to detect and locate microseismicity associated with CO2 storage reservoirs. Technologies such as SADAR will be an enabling driver as industries embark upon gigatonne storage capacities.