Influencing Factors of Corrosion Behavior of Carbon Dioxide Storage Wellbore

Through indoor carbon dioxide corrosion test, the integrity change law of the wellbore for storing carbon dioxide was studied. The results showed that carbon dioxide corrosion dissolved basic minerals such as fibrous or amorphous silicate gel (CSH) and Ca(OH)₂ in the wellbore cement ring, and the precipitation of weak gel and rod-like CaCO₃ minerals with high porosity eventually led to the deterioration of the strength and cementing performance of the cement ring, the increased of permeability, and the destruction of the integrity of the wellbore. With the increase of carbon dioxide temperature and partial pressure and the extension of corrosion time, the corrosion of the cement ring intensified, and the integrity of the wellbore of the storage well reduced. When designing carbon dioxide storage and solidification, attention should be paid to the use of anti-corrosion cement in the high temperature and high carbon dioxide partial pressure corrosion well section to prevent corrosion from causing the failure of the wellbore seal.