Petroleum (Mar 2020)
CO2 corrosion behaviors of 13Cr steel in the high-temperature steam environment
Abstract
The study aims to explore the corrosion behaviors of 13Cr steel in the high-temperature steam environment. The corrosion behaviors of 13Cr steel were tested in CO2 auxiliary steam drive environment simulated with the HTHP autoclave. The corrosion morphology and product composition were explored by SEM, EDS, XRD and XPS. The exploration results showed the corrosion rate of 13Cr steel in the high-temperature steam environment was less than 0.04 mm/a. The corrosion behaviors of 13Cr steel were mainly affected by temperature and chloride ion concentration. Temperature inhibited steam condensation and the compactness of Cr-rich layer. With the increase in temperature, more droplets were adsorbed on the surface of 13Cr steel and the compactness of the Cr-rich layer is worse. Chloride ions affects the activity of Fe atoms in the metal matrix. When chloride concentration increased, Fe2+ concentration in the solution and FeCO3 content in the rich-Cr layer were increased and the rich-Cr layer became looser. Keywords: CO2 auxiliary steam drive, Temperature, Cl− concentration, Corrosion, 13Cr steel