埋地钢质管道阴极保护电绝缘测试方法应用分析

围绕近年来普遍出现的埋地钢质管道输油气站场和阀室电绝缘失效问题,结合已开展的80座站场和阀室的电绝缘测试结果,介绍了目前阴极保护系统电绝缘失效的现状及失效形式,以实际工程案例分别阐述了目前常用的电绝缘测试方法的适用性和应用条件。基于现场测试数据和电路模型,分析和探讨了现有电位法和漏电率法测量误差的成因,以及采用电流环法和电压法判断绝缘失效时的应用条件。此外,结合实际工程经验,介绍了外部搭接、导电介质沉积和绝缘装置失效等3种典型的埋地钢质管道电绝缘失效故障的特征,并推荐了不同电绝缘失效形式下的排查方法,可帮助测试人员快速准确地排查电绝缘失效故障。

Analysis on Application of Electric Insulation Testing of Cathodically Protected Underground Steel Pipelines

The paper based on electric insulation testing in eighty oil &gas stations and valve chests of cathodically protected buried steel pipelines to introduce the status and characteristic of electric insulation fault in Cathodic protection system, and the usability and application conditions of normal inspection methods for electric insulation troubleshooting. Depending on the actual testing data and electrical simulation model, the errors as well as the cause in some testing methods, such as potential measurement, current leakage rate measurement, have been analyzed. Moreover, the characteristic and performance of external lap, conducting medium deposition and insulation device failure, focused on these three typical electric insulation fault, the specific troubleshooting methods have been recommend, which could be useful for inspector to locate the fault quickly and accurately.