Improved Injection Schedules of CO2 for Pohang Basin, Yeongil Bay, South Korea: Regarding Field Security and Injection Effectiveness

Abstract Yeongil bay is a basin located in Pohang, South Korea. Numerous projects and researches have been conducted for carbon capture and storage in Yeongil bay. The objectives of most of studies were shifted from enhancing injection efficiency to ensuring safety of carbon dioxide (CO2) storage after the Pohang earthquake occurrence in 2017. In this research, we present a stepwise CO2 injection scenario, which gradually increases injection rate during early stage of CO2 injection period. Furthermore, we conduct sensitivity analyses on an optimal stepwise CO2 injection scenario, based on the variations of permeability, well skin factor, and boundary condition between the storage site and aquifer. In conclusion, we can reduce the duration of CO2 injection compared to other injection scenarios which have suggested by previous studies with the same safety conditions and total amount of CO2 injected.