塔河油田聚烯烃内衬输油管线失效原因及防治措施

Failure Reasons and Prevention Measures for Polyolefin-Lined Oil Pipeline in Tahe Oilfield

采用宏观观察、微波扫描检测技术和ANSYS软件,对塔河油田聚烯烃内衬输油管线的失效类型、失效原因及防治措施进行了分析。结果表明:聚烯烃内衬输油管线主要失效类型为金属基管穿孔、法兰刺漏、钢包裹刺漏、塌陷、内衬层高温损坏和爆管;腐蚀性介质通过渗透至内衬层与金属基管之间的夹层中,随着服役时间的延长,金属基管发生CO_(2)-H_(2)S腐蚀;地势沉降导致聚烯烃内衬接头钢圈断裂,造成原油泄漏;腐蚀性介质渗透至内衬层与金属基管之间的夹层中,在管线清管泄压过程中,内衬层未完全恢复形变处以及局部划伤处内衬优先发生塌陷;当聚烯烃内衬层运行温度和运行压力超过其设计温度与设计压力时,内衬层会发生高温损坏和爆管。

The failure types,failure causes and preventive measures of polyolefin-lined oil pipelines in Tahe oilfield were analyzed by macroscopic observation,microwave scanning drtection techniques and ANSYS software.The results showed that the main failure types of polyolefin-lined oil pipeline were metal base pipe perforation,flange puncture,steel wrapping puncture,collapse,high temperature damage of lined layer and tube burst.The corrosive medium penetrated into the interlayer between lined layer and metal base pipe,and with the prolongation of service time,CO_(2)-H_(2)S corrosion occurred in metal base pipe.The subsidence of terrain caused the fracture of steel ring of polyolefin-lined joint,resulting in the leakage of crude oil.The corrosive medium penetrated into the lined layer between lined layer and metal base pipe,during the pigging and pressure relief process of the pipeline,the lined layer collapsed preferentially at the places where the liner layer did not fully recover deformation and local scratches.When the operating temperature and operating pressure of polyolefin-lined layer exceeded its design temperature and design pressure,the lined layer suffered from high temperature damage and tube burst.