Geomechanical challenges during geological CO2 storage: A review

•Geomechanical risks are expected due to the pore pressure buildup during CCS.•Geomechanical risks lead to the environmental concerns and adversely affect the public.•Potential geomechanical risks, such as CO2 leakage, seismicity, uplift, are reviewed.•Mechanisms, theories, and challenges are discussed with the relevant studies. Carbon capture and sequestration (CCS) method is the only viable method for reducing massive amount of carbon dioxide (CO2) from the atmosphere to prevent the subsequent environmental and health threats. However, the process is accompanied with geomechanical risks due to the unavoidable pore pressure buildup, such as caprock failure, reactivation of existing faults, poroelastic response of rock and well integrity loss. Not only may the risks lead to undesirable environmental concerns such as CO2 leakage to the surface, induced seismicity, and surface uplift, but it also would disturb achieving the public’s consensus on the CCS process. In this paper, we present an overview of possible geomechanical risks during CCS. We also review the mechanisms and theories of possible geomechanical risks during the CCS and the relevant precedent studies are introduced and described. This study would facilitate understanding the potential geomechanical risks during the CCS and establishing the optimal design of the CCS process to achieve the public acceptance. Some challenges related to handling the geomechanical risks during the CCS are also discussed.