Well Cement Degradation and Wellbore Integrity in Geological CO2 Storages: A Literature Review

Abstract: Carbon capture and storage (CCS) has emerged as the most effective method to curb the CO2 concentration in the atmosphere. It can store up to 5 billion tons of CO2 per year. To guarantee a safe and economical geological storage, the well cement degradation and wellbore integrity need to be studied thoroughly. This review paper is designed to provide a fundamental background of well cement degradation and wellbore integrity in geological CO2 storages to support the researchers in further investigation. The review mainly focuses on mechanical, thermal, chemical property changes and corrosion time for cement in experiments and simulation during geological CO2 storage. However, the debonding interface between casing/cement or cement/formation has not been addressed profoundly. A further investigation should inspect how pressure, temperature, and chemical reaction affect the micro-annuli of casing/cement or cement/formation. Also, a mathe-matical model should be established to predict the corrosion rate in geological CO2 storage.