黄土塬区原油集输管道腐蚀检测及剩余寿命预测

Study on the Corrosion Detection and Residual Life Prediction of Oil Gathering and Transportation Pipelines in the Loess Plateau

为了识别壁厚减薄原因,掌握管道运行状态,以XFZ转油站至WTL联合站埋地集输管道为研究对象,绘制腐蚀开挖检测专题图,开展腐蚀产物特性、边缘腐蚀状态试验研究,预测管道剩余寿命。结果表明:目标管道以内腐蚀为主,腐蚀点沿内壁随机分布,腐蚀速度级别为"重",腐蚀程度级别为"严重";腐蚀类型为Cl+O_2+CO_2+H_2O环境下的垢下腐蚀,以溶解氧、CO_2腐蚀为主,Cl^-腐蚀为辅;腐蚀原因为介质含水率较高,流速偏低,水中含有溶解氧和CO_2,且Cl^-含量过高;目标管道最大剩余寿命为3.52年,平均剩余寿命为2~3年,F管段已达到剩余寿命极限需立即更换。

In order to identify the causes of internal wall thickness loss and grasp the running state of pipelines, aiming at the oil gathering and transportation pipeline buried in the ground from Xueyi transfer station to Wusan joint station, the map of corrosion detection with excavation was made, the characters of corrosion products and state of edge corrosion were studied, the residual life of oil pipeline was predicted. The results showed that： for this research object, the corrosion points were randomly distributed along the internal wall of pipeline, the level of corrosion rate was the ＂heavy＂, and the level of corrosion degree was the ＂severe＂; the corrosion types were underdeposit corrosion in the Cl＋O_2＋CO_2＋H2_O environment, dissolved oxygen（O_2） and carbon dioxide（CO_2） corrosion were mainly, and chloride ion（Cl^-） corrosion was secondary; the corrosion causes were higher water content ratios, lower flow velocity, small amount of dissolved oxygen and carbon dioxide, and higher chloride ion contents of medium in oil pipeline; the maximum remaining life prediction was 3.52 years, the average was 2~3 years; and the test sample pipeline No.F, which had reached the limit of remaining life, should be replaced immediately.