耐蚀合金油管与高钢级碳钢套管在钻井液中的电偶腐蚀行为研究  

Study on Galvanic Corrosion Behavior of Corrosion Resistant Alloy Oil Tubing and High Grade Carbon Steel Casing in Drilling Fluid

作　　者：朱达江[1] 范宇 张华礼 李玉飞[1] 张林[1] 宋洋 ZHU Da-jiang;FAN Yu;ZHANG Hua-li;LI Yu-fei;ZHANG Lin;SONG Yang(Engineering Technology Research Institute,PetroChina Southwest Oil and Gas Field Company,Chengdu 610017,China;Xi’an Maurer Petroleum Engineering Laboratory,Co.,Ltd.,Xi’an 710065,China)

机构地区：[1]中国石油西南油气田分公司工程技术研究院,四川成都610017 [2]西安摩尔石油工程实验室股份有限公司,陕西西安710065

出　　处：《材料保护》2022年第9期27-33,40,共8页Materials Protection

基　　金：中国石油勘探与生产分公司项目(kt2020⁃14⁃02);中国石油西南油气田公司科研项目(20200302⁃12)资助。

摘　　要：为了解掌握井下油套管钢的腐蚀类型、严重程度及耐蚀性能,通过扫描电镜、能谱仪和金相显微镜对028镍基合金油管、140ksi碳钢套管材质在模拟某气井井下钻井液环境中的腐蚀形貌、产物进行了分析,并对单一材质均匀腐蚀和2种材质耦合后的电偶腐蚀行为进行了评价,分析了其影响因素及腐蚀机理。结果表明:在本次模拟工况下,028镍基合金油管单一腐蚀和电偶腐蚀情况均极其轻微,耐蚀性能优良;140ksi碳钢套管单一腐蚀、电偶腐蚀速率分别为0.2106 mm/a和1.5283 mm/a,分别属于严重腐蚀和极严重腐蚀。结论认为:当存在电偶腐蚀条件时,会进一步加剧碳钢套管的腐蚀程度。在酸性气井管柱设计时,应针对井下实际工况条件,不仅要考虑单一材质的防腐性能,还要考虑各种材质耦合接触时的电偶腐蚀,合理选择管材组合,降低或避免出现电偶腐蚀,同时制定有效的防腐措施,确保气井管柱的长期完整性。Aiming at understanding the corrosion type,corrosion severity and corrosion resistance of downhole oil casing steel,scanning electron microscopy,energy dispersive spectrometer and metallographic microscope were utilized to investigate the corrosion morphology and products of 028 nickel⁃based alloy oil tubing and 140ksi carbon steel casing materials in the simulated downhole drilling fluid of a gas well.Additionally,the uniform corrosion of a single material and the galvanic corrosion behavior after the coupling of two materials were evaluated,and the influencing factors and corrosion mechanisms were analyzed.Results showed that under this simulation condition,the single corrosion and galvanic corrosion of 028 nickel⁃based alloy oil tubing were both extremely slight,and the corrosion resistance of such tubing was excellent.In contrast,the single corrosion and galvanic corrosion rates of 140ksi carbon steel casing were 0.2106 mm/a and 1.5283 mm/a respectively,which indicated severe corrosion and extremely severe corrosion respectively.It could be concluded that the existence of galvanic corrosion conditions aggravated the corrosion degree of carbon steel casing.Thus,when designing sour gas well tubing strings,the combination of tubing materials should be chosen based on the actual downhole working conditions and taking into account not only the anti⁃corrosion performance of single material but also the galvanic corrosion resulting from the coupling contact of various materials,so as to reduce or avoid galvanic corrosion.Moreover,effective anti⁃corrosion measures should be worked out for ensuring the long⁃term integrity of gas well tubing strings.

关 键 词：028镍基合金油管 140ksi碳钢套管 钻井液 均匀腐蚀 电偶腐蚀 

分 类 号：TG172[金属学及工艺—金属表面处理]