超级15Cr马氏体不锈钢超深超高压高温油气井中的腐蚀行为研究

Corrosion Behaviors of Super 15Cr Martensitic Stainless Steel under Ultra-deep,Ultra-high Pressure and high Temperature Oil and Gas Well Environment

通过模拟油田超深超高压高温油气井腐蚀环境,研究超级15Cr马氏体不锈钢管材抗均匀腐蚀、点蚀、应力腐蚀开裂(SCC)及酸化液腐蚀的性能。研究结果表明:随着井深的增加,超级15Cr马氏体不锈钢的均匀腐蚀速率逐渐增大,且气相的均匀腐蚀速率要大于液相的腐蚀速率,但不论在液相还是在气相腐蚀条件下,均匀腐蚀速率均远小于0.1 mm/a;由于超级15Cr马氏体不锈钢有较高的Mo、Ni含量,在模拟腐蚀环境中未出现明显点蚀现象,具有良好的抗SCC性能;循环酸化腐蚀试验后试样管体和接箍部分没有出现点蚀、缝隙腐蚀等局部腐蚀迹象。通过经济性分析并综合考虑其抗腐蚀性能及油气井的经济性寿命,超级15Cr马氏体不锈钢可以作为超深超高压高温油气井油管材料使用。

By simulating ultra-deep,ultra-high pressure and high temperature oil and gas corrosion environment,the performance of super 15Cr martensite stainless tubular goods against uniform corrosion,pitting,stress corrosion cracking（SCC） and acid liquid was studied.The results indicate that the uniform corrosion rate of super 15Cr martensite stainless steel increases as the well depth increases.Further,the uniform corrosion rate of gas phase is higher than the one of the liquid phase.However,the uniform corrosion rate is far less than 0.1 mm/a regardless of corrosion conditions of liquid phase or gas phase.Since super 15Cr martensite stainless steel contains relative higher Mo and Ni element,obvious pit corrosion does not occur under simulating corrosion environment with excellent performance against SCC.After the cyclic acid corrosion test,local corrosion did not occur either to both the pipe body and coupling,including pitting,crevice corrosion,etc.By economic analysis and through comprehensive consideration of its anti-corrosion property as well as the economic life of oil-gas well,super 15Cr martensite stainless steel can be used as tubing materials for ultra-deep,ultra-high pressure and high temperature oil-gas wells.