非接触式磁应力检测技术及其应用

非接触式磁应力检测技术是通过测量管道应力异常引起的附加磁场变化来识别管道本体损伤和缺陷,能够实现管体缺陷非开挖全面检测,对于无法进行内检测管道的安全检测具有一定现实意义。青海油田集输管道地处荒漠戈壁环境,管道周围磁场干扰相对较少,是应用非接触式磁应力检测的有利区域。管道磁应力检测应用及验证结果表明:当管道本体缺陷损伤程度较小时,磁应力检测结果准确率可达90%以上;当管道整体腐蚀较严重,存在泄漏点或非常严重缺陷时,磁应力检测会低估其严重程度,导致严重壁厚损失缺陷无法检出或检测结果不准确,应论证后使用。

Non-contact Magnetic Stress Detection Technology and Its Application

The non-contact magnetic stress detection technique can be used to detect base metal dam-age and defects by measurement additional magnetic field variations due to piping stress anomalies.It can realize the trenchless comprehensive detection of pipe body defects,which has certain practical significance for the safe detection of pipes that cannot be detected internally.The gathering and transportation pipeline in Qinghai Oilfield is located in the Gobi desert environment with relatively little interference around the pipeline,so it is a favorable area to apply non-contact magnetic stress detection.The application and verification results of pipeline magnetic stress detection show that when the defect damage degree of pipeline body is small,the accuracy of magnetic stress detection results can reach more than 90%.However,when the overall corrosion of the pipeline is serious,there are leakage points or very serious defects,the magnetic stress test will underestimate its severity,resulting in the failure to detect the defects with serious wall thickness loss or inaccurate test results,which should be used after demonstration.