某油田90℃井下环境中N80Q钢的CO_(2)腐蚀行为

CO_(2) Corrosion Behavior of N80Q Steels under 90℃ Underground Environment of Certain Oil Field

为了给某油田针对实际地下腐蚀环境的选材提供参考建议,使用高压釜模拟了油田地下腐蚀环境90℃、1.0 m/s下5Mn2、1CrRE和2Cr钢生产的N80Q钢管的CO_(2)腐蚀行为,使用扫描电子显微镜以及配套的能谱仪、X射线衍射仪对3种钢的腐蚀产物膜进行表征。结果表明:在90℃下这些钢种主要呈均匀腐蚀特征,平均腐蚀速率差异不大。腐蚀产物膜均呈双层结构,且较为致密,主要由FeCO_(3)和少量FeOOH构成。研究提出,Fe_(3)C在腐蚀产物膜中作为阳极可以生成FeCO_(3)和FeOOH,从而导致90℃下腐蚀速率显著下降。

In order to provide reference suggestions for selection of materials for the actual underground corrosion environment of a certain oil field,a high-pressure autoclave was used to simulate the CO_(2) corrosion behavior of N80Q steel pipes prepared by the 25Mn2,1CrRE and 2Cr steel under 90℃ and 1.0 m/s in the underground corrosive environment of the oil field.Additionally,scanning electron microscopy,energy dispersive spectroscopy and X-ray diffraction were utilized to characterize corrosion product films of three types of steel.Results showed that the three steels mainly exhibited uniform corrosion characteristics at 90℃,and the difference in average corrosion rates was not significant.Meanwhile,the corrosion product films consisted of a relatively dense double-layered structure,and their composition were main FeCO_(3) and a small amount of FeOOH.The research suggested that Fe_(3)C as an anode in the corrosion film could generate FeCO_(3) and FeOOH,which led to a significant decrease in corrosion rate at 90℃.