Corrosion Behavior of N80s and P110s in Medium and High Temperature Areas in Acidic Media

In order to better understand the corrosion behavior of sulfur-resistant tubing steel in acidic media systems containing CO2 and H2S, using high temperature and high pressure reactor equipment, combined with SEM and XRD analysis methods, the corrosion behavior of N80s and P110s sulfur-resistant tubing steel in simulated lower ancient gas reservoir environment was studied. The corrosion rate under different temperature conditions was calculated, the corrosion morphology and composition were analyzed, and the corrosion mechanism was discussed. The results show that the two kinds of sulfur-resistant steels are mainly H2S corrosion in the range of 50 ℃–120 ℃. The corrosion of P110s steel is more serious than that of N80S steel. The product film composition is FeS, Fe1-xS, no FeCO3, corrosion rate decreases first and then increases, the extent of local corrosion gradually increases with the increase of temperature. It provides a theoretical basis for the material selection of acidic medium block in oil and gas fields, especially in middle and high temperature area, and provides a reference for the formulation of on-site anticorrosion measures.