Methodology to optimize the sizing of a corrective measure in case of leakage from a CO2 geological storage unit

• We propose a methodology for the choice and the sizing of a corrective measure.
• The methodology is adapted for a leakage from a CO2 geological storage site.
• The proposed methodology enables trade-offs between conflicting criteria.
• The implementation on a case study illustrates the methodology applicability.

To guarantee the safety of CO2 storage operations, to meet regulatory requirements and thus to be accepted by the public, the operator of a CO2 storage site has to demonstrate that the risks are adequately managed, which includes the treatment of potential irregularities. This paper proposes a methodology to choose a corrective measure and to optimize its sizing in case of leakage from a CO2 geological storage through a semi-pervious caprock, a fault, a fractured zone or any other leakage pathway on which it is difficult to directly act. The corrective measures considered in our work are limited to fluid and pressure management practices implemented for controlling the plume migration and eventually for extracting the leaking fluid. The methodology is based on the use of the Multi-Attribute Utility Theory (MAUT) which enables multi-criteria analysis over a continuous set of alternatives. The implementation on a case study illustrates the methodology applicability. The influence of the main assumptions and uncertainties are addressed through a sensitivity analysis.