Research on Corrosion Rate of Sucker Rod Steel 20Ni2Mo in Wet H2S Environment

Among the factors to cause the corrosion in oil and gas fields, H2S is the most common and harmful corrosive medium. During oil field exploitation, enhancing the ability of the sucker rods to resist corrosion is the key measure of prolonging the service life of sucker rods and guarantee of safe operation of petroleum equipment. This paper focuses on the corrosion of sucker rod steel 20Ni2Mo in different concentrations or temperatures of H2S. The appearance of corrosive surface scanned by scanning electron microscope was analyzed and theoretic basis for anti-corrosion and material-selecting of sucker rods used in the oil fields was provided. The result shows that the concentration and temperature of H2S have interaction on the corrosion of 20Ni2Mo, i.e., with the increase of concentration under same temperature or with the rise of temperature under same concentration, the corrosion rate of 20Ni2Mo accelerates.