A Study of Caprock Integrity in Geological CO2 Sequestration by Using Passive Seismic Monitoring System Based on 5G network

Caprock stress is redistributed as large quantities supercritical carbon dioxide (CO
₂
) are being injected into full scale storage sites. The cracks and failures of caprock allow the leakage of CO
₂
being sequestrated, which are fatal threats to the surrounding environment and ecosystem. In this study, a uniaxial compressive load is applied to the granite sample to analyze the failure procedure for the long-term in-situ caprock integrity by using passive seismic monitoring. As the sample fails under the compressive load, the induced seismic waves are recorded while the initial locations of seismic events are calculated by the Geiger algorithm. Later the frequency of seismic events is correlated with the failure evolution. Finally, the magnitude of the seismic events are evaluated based on the b value variations. In the field, the sensors would transfer the data by 5G network. The results show that the passive seismic system can map the caprock failure procedure.