Comparison of initial stress state and rock-failure risks for five prospective CO2 storage sites

We report initial assessments of the state of stress and the estimated conditions for rock failure at five prospective CO2 storage sites which are being considered in the ACT SHARP Project. This multinational project aims to improve understanding of stress history and reservoir pressure to enable improved quantification of CO2 storage containment risks. The goal is to improve the accuracy of subsurface CO2 storage containment risk management through the improvement and integration of subsurface stress models, rock mechanical data and seismicity observations. The case studies considered in this assessment are: • Norway – Horda/Smeaheia region; • UK – Southern North Sea, Bunter storage play; • Netherlands – Aramis site, Rotliegend pre-salt; • Denmark – Lisa Structure; • India – Bhagewala Heavy Oil Field, Rajasthan. These case studies have different levels of maturity of site development and data availability, which is useful for understanding what data is needed at different stages of a project. While detailed site characterisation and rock failure studies have been conducted for the Horda/Smeaheia region offshore Norway and for parts of the UK Southern North Sea (SNS) Bunter storage play, rock failure characterisation studies at the Aramis site and Lisa Structure are limited to regional studies. The Bhagewala Heavy Oil Field in India is the least mature of the case studies in terms of storage assessment.