Abstract
Summary Carbon capture and storage (CCS) has emerged as a critical technology in response to global climate commitments, such as those set out in the Paris Agreement. One of the most crucial elements for successful CO2 sequestration is the mechanical and hydraulic integrity of the caprock, particularly when intersected by fault zones. Fault gouge material, a fine-grained composition often formed from crushed rock along faults, plays a pivotal role in either facilitating or impeding CO2 migration. Despite its importance, the permeability behavior of gouge under realistic subsurface conditions remains poorly understood. This study investigates the relationship between permeability and confining pressure using artificial fault gouge samples, helping to bridge this knowledge gap with implications for risk assessment and site selection in CCS operations.