Feasibility study of geological storage of CO₂ in carboniferous UK’s Bowland shale formation from geochemical perspective

CO₂ geological storage is commonly acknowledged as a viable key technology for reducing the effect of CO₂ emissions on global climate change. In terms of sedimentary rock types, shale formation is predominantly clay minerals and is one of the most prevalent. Due to their wide availability, advantageous mineralogy, and pore structure, shale formations have become an effective alternative for CO₂ storage. However, because of the high reactivity of carbon dioxide to shales, the mineralogical alteration after CO₂/ brine/shale interaction plays a crucial role in determining the sealing properties of shales at the geological time scale. This study uses an analytical approach to investigate the feasibility of the Bowland shale formation in the United Kingdom for CO₂ storage. The main influential parameters, such as salinity and brine composition, were investigated during carbon dioxide storage. The result showed that the formation of carbonic acid caused the clay mineral (kaolinite and illite) to dissolve in the CO₂-saturated brines, whereas the quartz precipitated. This gives an excellent possibility for mineral trapping, which is considered an efficient CO₂ trapping mechanism.