某超深井油管腐蚀开裂分析及对策研究

Analysis and Countermeasures of Corrosion Cracking of an Oil Pipe

现有的酸液缓蚀剂对消除高温环境下酸性高浓度盐水对超级13Cr材质油管的应力腐蚀是无效的,实际生产应用中导致了应力腐蚀开裂,需研发新型缓蚀剂解决高温酸液及高温酸性高浓度盐水的应力腐蚀。研究已有缓蚀剂缓蚀机理的基础上,分析了其不足之处,提出了聚合成膜的缓蚀机理,即利用一些化合物在酸液环境中在一定条件下相互反应,生成含至少2个活性功能团中间产物,可在金属表面快速生成聚合物膜。基于该理论,研发了新型缓蚀剂,在高温高压动态腐蚀速率测量仪测试,180℃下,15%盐酸腐蚀速率最低为16.0 g/m^(2)·h;四点弯曲法测试证实该缓蚀剂显著消除了酸性高浓度盐水在高温环境中对超级13Cr材质试片产生的应力腐蚀开裂。新型缓蚀剂可有效减少超级13Cr材质油管在超深高温高压气井中产生的应力腐蚀开裂。

Existing acid corrosion inhibitors are ineffective to eliminate the stress corrosion of acidic high-concentration brines on super 13Cr material oil pipes under high temperature environments.In actual production applications,stress corrosion cracking is caused,and new corrosion inhibitors need to be developed to solve high temperature acids and high temperatures.Stress corrosion of acidic high concentration brine.Based on the research on the corrosion inhibition mechanism of existing corrosion inhibitors,the shortcomings are analyzed,and the corrosion inhibition mechanism of polymerized film formation is proposed,that is,some compounds are used to react with each other under certain conditions in an acid environment to produce a solution containing at least 2 An intermediate product of an active functional group can quickly form a polymer film on the metal surface.Based on this theory,a new type of corrosion inhibitor was developed,which was tested by a high-temperature and high-pressure dynamic corrosion rate measuring instrument.At 180℃,the minimum corrosion rate of 15%hydrochloric acid was 16.0 g/m^(2)·h;four-point bending test confirmed that the corrosion inhibitor was significantly eliminated The stress corrosion cracking of the super 13Cr material test piece produced by acidic high-concentration brine in a high-temperature environment.The new corrosion inhibitor can effectively reduce the stress corrosion cracking of super 13Cr material tubing in ultra-deep high temperature and high pressure gas wells.