Geochemical Modelling of the Evolution of Caprock Sealing Capacity at the Shenhua CCS Demonstration Project

摘要: CO2 geological storage is considered as an important measure to reduce anthropogenic emissions the atmosphere for addressing climate change. The key prerequisite long-term sealing capacity of caprock. This study investigates evolution caprock induced by geochemical reactions among CO2, water and using TOUGHREACT code based on Heshanggou Formation mudstone at Shenhua Carbon Capture Storage (CCS) demonstration site China. results show that self-sealing phenomenon occurs in lower part dominated precipitation dawsonite, magnesite, siderite, Ca-smectite illite. While self-dissolution upper mainly due dissolution kaolinite, K-feldspar, chlorite Ca-smectite. Sensitivity analyses indicate siderite highly advantageous leading caprock, with albite providing Na+, Mg2+ Fe2+. K-feldspar dominates illite required K+, affects precipitation. are enhanced significantly increasing temperature, while effect salinity negligible perhaps low level formation water.