Determining the risk of CO₂ leakage along fractures in caprocks using an integrated monitoring and hydro-mechanical-chemical approach, DETECT

DETECT aims to significantly improve our ability to evaluate risks of leakage across faulted and fractured caprocks, so as to better inform operators, regulators and other stakeholders in their risk mitigation strategies. The results from this study will be incorporated into CCS industry leading guidance documents which will allow stakeholders to:

1.            perform effective caprock and seal integrity risk assessment

2.            communicate clearly and logically assessed caprock integrity risks

3.            understand realistic leakage rates and related implications

4.            select realistic and efficient leak rate modelling approaches

5.            select reliable, cost effective and innovative containment monitoring technologies

6.            demonstrate quantitative risk assessment applicable beyond investigated risks

All of these elements will substantially contribute to accelerating implementation of the CCS technology by providing pragmatic and reliable tools to reduce risks and costs for CO₂ storage operations. Specifically, DETECT will deliver an integrated approach to (qualitatively and quantitatively) determine the risk of natural leakage across the primary caprock. Key targets of DETECT are:

1. Laboratory experiments to determine impact of:

– reservoir stress changes on fracture flow properties

– chemical reactions on fracture flow properties

– swelling clays on fracture flow properties

2. Field studies to characterize fault and fracture network geometries

3. Hydro-mechanical-chemical modelling to determine:

– Flow in a single fracture and connected matrix

– Potential for upscaling of flow in fault damage zones

– Fault zone leak path modelling of storage complexes

4. Containment monitoring technologies:

– Identify monitoring technologies suitable to detect leakage across caprock and determine expected performance

5. Integrated qualitative and quantitative risk assessment:

– Determine safeguards and generate guidance bowties for efficient risk assessment

6. Dissemination to assure uptake of results