Probabilistic framework for risk-adjusted cost analysis of carbon-storage monitoring: insights from non-traditional sensing technologies

• Probabilistic cash flow model links monitoring cost to containment failure. • Framework adapts to any site via area, depth, and well number inputs. • Downhole seismic allows 4D seismic interval to be extended at minimal risk increase. • Joint use of downhole seismic with 4D seismic lowers risk-adjusted monitoring cost. • False positive probability strongly drives risk-adjusted monitoring cost. Carbon Capture, Utilisation and Storage (CCUS) can help abate CO 2 emissions as we transition to a more decarbonised economy, although high costs associated with CCUS can deter its deployment. Here, a probabilistic methodology is developed for the estimation of the risk-based cost of remediation in case of a failure of carbon dioxide containment, as well as the lost opportunity if the CCUS project is decommissioned before its projected lifetime. Six different migration outcomes are considered, covering a range of possible primary containment failure and early project decommissioning events. These risk-based costs (RISKEX) are combined with capital (CAPEX), operating (OPEX) and decommissioning expenditures (DECOMEX) to determine the total cost of monitoring, providing a comparative, quantitative method for comparing the economic viability of monitoring suites incorporating the economic risk associated with failure. A sensitivity analysis is conducted on the main cost assumptions and detection parameters, to provide insights into the main economic drivers of monitoring and containment risk management costs. Results show that although incorporating highly accurate non-traditional monitoring technologies (NTMTs) alongside conformance monitoring increases CAPEX and, to a lesser extent, OPEX, these costs can be partially offset by a slight reduction in RISKEX. A higher ratio of late to early detection remediation costs, and a low probability of false positive can significantly increase the economic feasibility of implementing monitoring techniques. The incorporation of NTMTs may also enable decreasing the frequency of conformance monitoring.