非开挖NoPig检测技术发展现状与应用前景

NoPig技术是国外研发的一种新型非开挖地面检测技术,能够有效用于76.2～914.4mm直径的油、气、水等钢质管道腐蚀缺陷的在役无损检测作业。NoPig检测技术的基本工作原理是:在待测管段两端通以多成分谐波电流,测量管道上方的磁场,进而获得该电流的频谱和磁场的频谱;通过对比分析多成分谐波电流和磁场各同谱分量的比值,最终确定壁厚的异常变化范围。该技术目前已广泛应用于非开挖埋地油气管道的管体缺陷检测,德国Eon/Ruhrgas和VNG管道运营公司、澳大利亚RAG公司和Applus RTD公司已有应用实例。应用结果表明:该检测技术特别适用于无法清管的油气管道,对于管道缺陷的轴向定位具有较高的准确度,同时可极大降低检测工作难度,显著节省管道检测费用,具有广阔的应用前景。

The application and prospect of trenchless NoPig inspection technique

NoPig technique is a new trenchless inspection technique developed by N.P.Inspection Company.It is suitable for the in-service defect inspection for the steel pipelines transporting oil,gas and water.The pipe diameter ranges from 76.2 mm to 914.4 mm.The basic principle of NoPig technique is that multi-harmonic current is activated onto the proposed both ends of pipe to measure the upward magnetic field of pipe,and further to display the frequency spectrums of the current and magnetic field.The ratio between these two spectrums are evaluated to finally recognize the changing range of pipe wall.Currently the technique is extensively applied in trenchless inspection for oil & gas transmission pipeline.Eon/Ruhrgas and VNG Pipeline Operation Company,Germany,RAG Company,Australia and Applus RTD Company have already performed their applied study.Research shows that it is suitable for non-piggable pipelines and bears high axial positioning accuracy.NoPig technique makes pipeline inspection easier,reducing inspection cost,owning a broad future.