Corrosion adaptability evaluation of metal materials for packers in bozhong 19-6 gas field

Corrosion behavior of six kinds of metal materials, 35CrMo carbon steel, 42CrMo carbon steel, HS110 sulfur-resistance steel, 13Cr stainless steel, supper 13Cr stainless steel (13CrS) and 2205 duplex stainless steel was studied through corrosion tests in the environments of simulated downhole working conditions of Bozhong 19-6 gas field. The corrosion rates of the metals were calculated by weight loss method, the corrosion morphology of metals was observed by scanning electron microscopy (SEM), and the composition of corrosion products was analyzed by Xray photoelectron spectroscopy (XPS). The results showed that the corrosion rate rank from large to small were as follow: HS110>35CrMo>42CrMo>13Cr>13CrS>2205. And the corrosion rates of all the metal materials in liquid phase were higher than those in gas phase. It is recommended to use 13CrS and 2205 as central tube material, and use 42CrMo for slip and other functional units.