A methodology for monetizing basin-scale leakage risk and stakeholder impacts

Carbon dioxide (CO₂) capture and storage involves injecting CO₂ into permeable geologic reservoirs. Candidate reservoirs will be overlain by an impervious caprock, but CO₂ or brine may leak through this caprock via natural or manmade pathways into overlying units. Such leakage will incur multiple costs to a variety of stakeholders, as mobile fluids may interact with other subsurface activities, reach groundwater, or possibly escape from the surface. We summarize a methodology to monetize leakage risk throughout a basin, based on simulations of fluid flow, subsurface data, and estimates of costs triggered by leakage. We apply this methodology to two injection locations in the Michigan (U.S.A.) Sedimentary Basin, and show that leakage risk is site-specific and may change priorities for selecting CO ₂ storage sites, depending on its siting relative to leakage pathways and other subsurface activities.