摘要
Abstract
Solution immersion environments containing H2S/CO2 and acetic acid were simulated in a high temperature and high pressure autoclave manufactured by UAS Cortest Company, and test was conducted in flowing H2S/CO2 medium with high salinity. The Effect of H2S on CO2 corrosion of oil tube steel were analyzed and discussed by the following electrochemistry technologies, such as SEM, XRD, dynamic potential scanning, AC impedance and etc. The results showed that the corrosion rate of N80 oil tube steel is very high, up to 5.1mm/a, when solution immersion environment contain only CO2 and acetic acid. However, with the addition of H2S, the corrosion rate is restrained obviously and the largest decreasing point is observed at the lowest partial pressure of H2S, down to 0.28 mm/a. With H2S partial pressure increasing, the corrosion rate slightly increased, but is far lower than simplex CO2 corrosion rate. With the presence of H2S, the corrosion products are mainly FeS (Mackinawite), FeCO3 doesn't appear, and corrosion is controlled by H2S. The corrosion forms of samples are mainly localized corrosion, severe pitting presents on surface of samples, and exist of acetic acid promotes the tendency of pitting of oil tube steel in H2S/CO2 environment关键词
油管钢/高温高压/H2S/CO2腐蚀/醋酸/点蚀Key words
oil tube steel/ high temperature and high pressure/ H2S/CO2 corrosion/ acetic acid/ pitting分类
矿业与冶金
