(685f) Monitoring Ions Based on Reactive Transport Modeling of CO2 Sequestration in Ulleung Basin, Korea

 In Carbon Capture and Storage(CCS) process geochemical monitoring technology plays important role to avoid potential CO2 leakage. In this paper, reactive transport modeling of supercritical CO2 in aquifer which is modeled after Ulleung basin; one of offshore geological storage site of Korea was performed. Supercritical CO2 have been injected into target reservoir at the rate of 30kg/s for 30 years. After injection for 30 years, long-term behavior of the CO2 by considering its geochemical reaction for 5000 years was investigated. In early stage, aqueous phase and supercritical CO2 was dominant. After 800~1000years, mineral phase became dominant phase accounts for more than 80% of injected CO2. During injection period, at monitoring points, manganese, bicarbonate ions concentration changed before reaching supercritical CO2. Ion concentration changes can give early warning of potential CO2 leakage. To determine monitoring ions for specific mineral composition, reactive transport modeling of typical mineral composition cases for geological storage reservoir all over the world was conducted.