Optimization of plugging design for well abandonment- Risk management of long-term well integrity

Abstract A part of MOVECBM EU project is dedicated at evaluating the long-term wellbore integrity on the basis of a risk perspective. This i mplies, among others, to optimize the plugging strategy, in order to mitigate risk associated to CO 2 migration inside the well during the abandonment phase (i.e. post injection). The role of containment of well’s components has to be ensured for hundreds of years, despite degradation mechanisms (i.e. ageing) that affect their properties. To mitigate risk associated to CO 2 leakages, a probabilistic study was dedicated to casing corrosion in order to support the design of the plugging strategy and its optimization. This was achieved with calculations based on in-situ data and taking into account uncertainties. Results of this study enable to get objective criteria to support the decision process for efficient plugging design for the MS-3 well (vs. wellbore integrity perspective).