Evaluation of the physical and economic potential of surfactant-based CO2 capture and storage in a saline aquifer

Carbon dioxide (CO 2 ) storage in saline aquifers is considered essential to reduce CO 2 emissions. However, the pressure buildup associated with CO 2 injection [conventional CO 2 capture and storage (CCS)] into such reservoirs constrains dynamic storage. Studies have shown the benefits of surfactants in CCS, alleviating the pressure buildup and improving CO 2 injectivity. However, these studies examined only the surfactant benefits without considering the associated costs, which compromise the adaptability of surfactant use beyond the experimental scale. Thus, an estimate of the potential costs of surfactant-based CCS is needed to facilitate surfactant use on a field scale. This study evaluated the economics of surfactant-based CCS in a saline aquifer. We used the MATLAB Reservoir Simulation Toolbox (MRST–CO 2 lab) to forecast the long-term behavior of the injected CO 2 and examine the optimal injection rate that can be achieved with and without surfactant. We constructed an economic model that encompasses the CO 2 capture, transport, and storage costs calculated using Indonesian, European, and U.S. standards and applied it to the Johansen formation in the Norwegian Sea. We used U.S. and European CO 2 emission tax credit policies to assess the net present value (NPV) of the CCS project with and without surfactant injection, which is a more realistic way to evaluate surfactant-based CCS development compared with other studies. The results show that CCS is more sensitive to the reservoir storage capacity and CO 2 emission tax credit, such that a small storage reservoir entails a higher cost and requires a higher CO 2 emission tax credit to offset the capital investment. The use of surfactants alleviates the higher CCS cost by increasing the injection rate, and CCS facility sharing can reduce the cost of CO 2 transport to the injection site. Therefore, further analysis is needed to quantify both conventional and surfactant-based CCS at a regional level.