Corrosion Behavior of Several Thermal Recovery Well Tubular Steels in Secondary H₂S/CO₂ Environment

The corrosion behavior of ordinary carbon tubular steel N80 and two thermal recovery well tubular steels TP100H and TP110H in heavy oil thermal recovery secondary H₂S/CO₂ corrosive environment was studied in high-temperature and high-pressure autoclave. The results show that the corrosion rate of N80 steel was the lowest in three kinds of steels due to the characteristic of non-uniform corrosion. Both the TP110H steel and the TP100H steel had the corrosion rate slightly higher than that of the N80 steel, and presented uniform corrosion characteristics after removal of corrosion products. The corrosion rates of these three kinds of steels were consistent with their characteristics of microscopic appearance. With the increase of corrosion time, the surface roughness increased and the corrosion rate reduced correspondingly for three kinds of steels.