A Short Review on Oil Well Cement Alteration in Geological CO2 Storage

The global average temperature of the Earth is increasing due to the concentration of the anthropogenic greenhouse gases in the atmosphere. Carbon dioxide (CO2) is of one the main released gases from the heavy industries such as utility power plants. One of the efficient solutions to tackle the problems caused by CO2 emission into the atmosphere is carbon capture and storage (CCS). In concept, the captured carbon can be successfully sequestered by being injected into the underground formations, where it is expected to remain for thousands of years. Promising target sites to store this CO2 are depleted oil and gas reservoirs. Although it such sites seem ideal, these abandoned oil and gas wells can prove to be significant CO2 leakage points due to the quality of the cement used in the initial well bore casings and the caps at the end of their productive life. These possible sources of CO2 will compromise the entire CCS scheme for that location. Due the wells being direct connections between the stored fluid and the surface. The current study provides a review of studies conducted on the alteration in performance of typical well casing and capping cements due to exposure to CO2-bearing fluid.