南疆利民管道阀室内埋地管线阴极保护漏电检测分析  

Detection and Analysis of the Cathodic Protection Leakage of the Buried Pipeline in the Valve Chamber of Limin Pipeline in Southern Xinjiang

作　　者：李晓波[1] 刘宗胜[1] 王民[1] 谢锡林[1] 王荫刚 LI Xiaobo;LIU Zongsheng;WANG Min;XIE Xilin;WANG Yingang(South-Western Tarim Exploration and Development Company,Tarim Oilfield Company;Downhole Operation Branch of Bohai Drilling Engineering Co.,Ltd.,CNPC)

机构地区：[1]塔里木油田分公司塔西南勘探开发公司 [2]中国石油集团渤海钻探工程有限公司井下作业分公司

出　　处：《油气田地面工程》2019年第6期69-72,共4页Oil-Gas Field Surface Engineering

摘　　要：南疆利民长输管道和田—民丰段管线进出阀室无绝缘接头设计,一旦阀室内的电气系统接地导致管道接地搭接或绝缘失效,将造成埋地管道处于欠保护状态,引起阀室内管道腐蚀。采用交流电流衰减法及密间隔电位法对和民干线44号阀室及46号阀室展开了阴极保护电流及阴极保护漏电分析,结果表明:当阀室存在阴极保护电流漏电时,感应电流信号有明显衰减,且管地电位明显比阀室外测试桩电位偏正。结合44号阀室及46号阀室试验结果,给出详细的阀室绝缘性能评估及阴极保护漏电原因分析方案,从而逐步分析出阀室内埋地管道阴极保护漏电原因。针对南疆利民长输管道检测出的部分阀室漏电情况,提出对漏电阀室管道连接的设备接地引下线安装固态去耦合器的预见性措施,解决了长输管道既要求绝缘,电气专业的设备又要求接地的矛盾。Due to the lack of insulation joint design in the valve chamber of Hetian-Minfeng segment in Limin Long- distance Pipeline in Southern Xinjiang, the buried pipeline will be under no- protection condition once pipeline ground lap or insulation failure caused by the electrical system ground connection, causing pipeline corrosion in the valve chamber. The cathodic protection electric current and cathodic protection electric leakage of no. 44 and no. 46 valve chamber in Hemin Pipeline are analyzed by the alternating current attenuation method and close interval potential survey method. Results show that the induced current signal has obvious attenuation and the pipe- soil potential is obviously positive than post potential outside of valve chamber when cathodic protection electric leakage exists in the valve chamber. Combined with the test result of no. 44 and no. 46 valve chamber,a detailed scheme to assess the insulation performance and root cause of cathodic protection electric leakage is provided, and then the cathodic protection electric leakage cause of the buried pipeline in the valve chamber is analyzed step by step. Aiming at the valve chamber leakage in Limin Long- distance Pipeline in Southern Xinjiang, the predictable measures to install solid decouple in the grounding line of equipment connected to the valve chamber pipeline is proposed,and this can effectively solve the dilemma between insulation needed by long-distance pipelines and grounding required by electrical equipment.

关 键 词：埋地管道 阴极保护 阀室 漏电 电位 

分 类 号：TE988.2[石油与天然气工程—石油机械设备]