新疆油田某稠油注采合一单井埋地管道腐蚀原因

Corrosion Causes of Buried Pipeline in a Heavy Oil Injection-Production Well in Xinjiang Oilfield

通过宏观观察、扫描电镜、激光共聚焦显微镜和能谱分析,结合电化学测试,分析了新疆油田某稠油注采合一单井埋地管道腐蚀穿孔的原因。结果表明:该管道外腐蚀严重,内腐蚀较轻微,外腐蚀穿孔是主要的失效模式;冷热交替导致管道防腐蚀层老化、破损严重,管道本体裸露在腐蚀介质中,这是管道外腐蚀减薄穿孔的直接原因;CO_(2)和O_(2)腐蚀、细菌腐蚀是造成稠油热采管线外腐蚀的重要原因;温度60℃时,外腐蚀最严重。

Through macroscopic observation,scanning electron microscopy,laser confocal microscopy and energy spectrum analysis,combined with electrochemical test,the causes of corrosion perforation of buried pipeline in a single well in Xinjiang oilfield were analyzed.The results show that the external corrosion of the pipeline was serious,the internal corrosion was slight,and the external corrosion perforation was the main failure mode.The alternation of cold and heat led to the aging and serious damage of the pipeline anti-corrosion layer,and the pipeline body was exposed in the corrosive medium,which was the direct cause of the corrosion thinning and perforation outside the pipeline.CO_(2)and O_(2)corrosion and bacterial corrosion were important causes of external corrosion of heavy oil thermal recovery pipelines.When the temperature was 60℃,the external corrosion was the most serious.