论文部分内容阅读
为定性研究长庆油田地层水对J55套管的侵蚀性，分别选取了国产和进口的J55套管试样各两种，模拟油田高温高压环境进行腐蚀试验。试验结果表明，试样表面均存在点蚀现象，4种试样的平均腐蚀速率最大为0．130mm／a，最小为0．074mm／a，相差很大。试样表面的腐蚀产物主要是FeS，说明在这种环境中，套管可能同时遭受CO2腐蚀、硫酸盐还原菌腐蚀、H2S腐蚀和垢下腐蚀，其中H2S腐蚀和垢下腐蚀引起的点蚀占主导。同时发现，试样腐蚀速率的差异和试样的金相及成分有密切关系。通过微合金化和提高材料的冶炼水平来降低P和S含量，以及通过适当的热处理使晶粒细化等方式可以提高套管材料的耐H2S和CO2腐蚀能力。
In order to qualitatively study the erosion of formation water of J55 casing in Changqing oilfield, two domestic and imported J55 casing samples were selected to simulate the corrosion test under high temperature and high pressure environment. The test results show that there are pitting corrosion on the sample surface, the average corrosion rate of the four samples is 0.130mm / a, the minimum is 0.074mm / a, the difference is very large. The corrosion products on the sample surface are mainly FeS, indicating that in this environment, the casing may also suffer from CO2 corrosion, sulfate-reducing bacteria corrosion, H2S corrosion and scale corrosion, of which pitting corrosion caused by H2S corrosion and scale corrosion leading. Also found that the difference between the sample corrosion rate and the sample’s metallographic and composition are closely related. Reducing the P and S contents by micro-alloying and raising the smelting level of the material, as well as the grain refinement by proper heat treatment, can improve the corrosion resistance of the casing material against H2S and CO2.