在役油气管线防腐蚀层老化的评价方法

为研究和评价在役长输油气管线防腐蚀层的质量,建立了反映涂层质量变化的简单数学模型,分析了防腐蚀层过渡电阻与长输油气管线的阴极保护电位分布规律的关系,从理论上了解防腐蚀层的漏失情况。结合工程现场的实测数据,通过标准管地电位(P/S)测试,绘制电位-距离曲线,推算绝缘层特性参数及管线沿线电位的衰减系数,对在役管线的防腐蚀层状况进行评估,从而为管网的维护提供相应依据,指导现场管道的安全运行。

Evaluation Methods of Aging of Corrosion Resistant Layer on In-service Oil and Gas Pipeline

Mathematical model reflecting the quality change of coating was built to study and evaluate the quality of corrosion resistant layer on in-service long-distance oil and gas pipeline,the relationship between the transition resistance of corrosion resistant layer and cathodic protection potential distribution of long-distance oil and gas pipeline was analyzed,the dropout situation of corrosion resistant layer was understood theoretically.At the same time,potential-distance curve was drawn according to standard pipe ground potential (P/S) testing and measured data from the project site,special parameters of the corrosion resistant layer and attenuation coefficient of the potential along the pipeline were calculated.Condition of the corrosion resistant layer on in-service pipeline was assessed,so as to provide an appropriate basis for the pipe network maintenance and safe operation guidance of the pipeline.