Characterisation of a potential CO2 storage complex and first-order containment risk assessment in the Cambay Basin, India

High-level studies have identified potential for subsurface CO2 storage in India, however lack of detailed technical appraisals aimed at understanding and de-risking the storage resource presents a major challenge to development of CO2 storage. The onshore Cambay Basin has been identified as a promising target for CO2 storage given its history of hydrocarbon production and proximity to emission sources. To expedite subsurface characterisation activities in the region, this study uses a 350 km2 3D seismic volume and well dataset to identify a stratigraphic succession suitable for consideration in a CO2 storage complex. The Middle to Upper Eocene Ankleshwar Formation comprises several potential reservoir and top seal units which may be considered for storage. A high-level assessment of the stratigraphic and structural characteristics of the Ankleshwar Formation is presented, along with a first-order assessment of the principal containment risks and associated uncertainties. Remaining uncertainties are identified along with suggested appraisal activities to reduce uncertainty and further de-risk the storage concept. Whilst there is considerable uncertainty related to the lateral migration of CO2 within the storage system, the high number of legacy wells in the study area presents the most significant risk to CO2 containment.