Abstract

Geologic carbon sequestration (GCS), a process to capture and store CO2 in deep geologic formations, is considered an essential technique to reduce carbon emissions which are a main cause of global warming and climate change. Depleted oil and gas reservoirs are among the most appealing locations for GCS. However, the success of the strategy relies on the long-term integrity of the reservoirs, which is challenged by the carbonation reactions between the main reservoir sealing material, i.e., cement, and the stored CO2 and then the occurrence of fluid leakage. This work provides a concise review on the degradation of oil well cement and the interface between cement and casing/formation rock, with a special focus on the influence of different factors such as the curing, service conditions and contaminants. The mechanisms and the mitigation methods of the degradation process are also discussed. This work aims to summarise current research progress and identify some remaining challenges for future research.