Tracking and CO2 leakage from deep saline to fresh groundwaters: Development of sensitive monitoring techniques

Abstract : In a predictive approach goal and to focus this work on risk assessment related to CCS context, a modeling study of an unfavorable scenario in which CO 2 leakage (willfully provoked) through an abandoned well, from a deep saline aquifer to fresh groundwater was developed. This 3D numerical model handles both fluid-rock geochemical interaction in the storage aquifer and impacted aquifer (code TOUGHREACT). In a second part and in the frame of studying, the use of multi-isotope approaches, like an isotopic monitoring opportunity, is developing in order to detect CO 2 leakage and to record geochemical processes of water quality evolution, induced by the lowering of the pH due to the ingress of CO 2 in the system. The case of study applies to the French Paris Basin.