Investigation of the Corrosion Characteristics and Corrosion Inhibitor Action on J55 Steel in Produced Water

The corrosion behaviour of J55 steel in typical high-water-cut oil wells and the inhibition effects of different types of corrosion inhibitors were investigated. Using electrochemical experiments, the effects of temperature, Cl-, HCO3-, Ca2+, Mg2+ and pH on the corrosion of J55 steel were studied. Under experimental conditions, the corrosion rate slowed with increasing pH value when the temperature increased from 35 degrees C to 70 degrees C. The corrosion rate also increased first and then decreased with increasing Cl-, Ca2+ and Mg2+ ion concentrations, which notably affected the distribution of corrosion pits on the surfaces of the steel. The protection performances of various corrosion inhibitors and corrosion products were evaluated through electrochemical measurements. The results showed that the CT-2, UT2-2 and YC-2 inhibitors had obvious effects on the corrosion prevention of the J55 steel. In particular, the corrosion inhibition efficiencies of the three kinds of carbon steel were remarkable and exceeded 84% when the UT2-2 concentration reached 0.18 g/L.