The role of fault characterization in CO2 containment risk assessment – a review

Fault zones are key structures controlling subsurface fluid migration and localization of deformations. Although faults have been extensively studied for decades, emerging CO₂ storage projects face challenges quantifying CO 2 fault leakage risk as part of the overall containment risk assessment. This review first outlines the role of faults in CO 2 containment risk with focus on fault zone mapping, architecture and models for fault seal integrity evaluation. Further, we emphasise the hydraulic and mechanical properties in mudrock faults and highlight advances in understanding hydromechanical coupling during fault reactivation based on insight from underground research laboratories. Finally, we discuss the implications for CO 2 containment risk and summarize future research needs for mudrock faults.