The Potential Effect of CO_2-Water-Rock Reaction on The Caprock Formation (Mudstone) Case Study

摘要

By using a 1D column geometrical model this paper carried out research on the effects of CO_2 penetration on the caprock properties. The result show that due to CO_2 ingression the formation water environment changed greatly. The pH reduced to 3.8 from initial 7.48 and then buffered to 5.6; The supercritical CO_2 reached to 0.006 m in the caprock, but aqueous CO_2 reached to 1.1 m. The self-sealing efficiency worked after about 25 years, and the relevant minerals were calcite, quartz, kaolinite and calcite. The research will provide some technical reference for site selection of CO_2 geological storage projects and CO_2 leakage assessment.