Microseismic monitoring network design for CO₂ sequestration

Microseismic monitoring of CO₂ sequestration requires an alternative network design. The current regulator practice (so-called Traffic Light Systems - TLS) are targeting at mitigation of hazards - such as felt or damaging induced seismicity. We review current practice in seismic monitoring and show that there is a wide range of approaches to microseismic monitoring resulting in inconsistent information and strategies. Thus, we propose a CO₂ sequestration suitable seismic monitoring system that not only accounts for felt seismicity but has distinct threshold levels and location resolution adapted to detect smaller events in the seal and reservoir. The monitoring requirements are proposed to be derived from geological properties of the reservoir and inform the operator or regulator to develop a corresponding and fit for purpose system that further manages induced seismicity to ensure storage longevity.