Research On3D MFL Inspection System Used In Pipeline Inspection

Pipeline transportation is the main way of international energy transport.70%of theworld’s oil,90%of the world’s natural gas is transported by pipelines. Pipelines aremostly laid in the underground or underwater, because of the transmission medium andsoil environment, pipeline corrosion is inevitable. Annual losses caused by pipelinecorrosion is tens of billions. This kind of pipeline failure can’t be found by helicoptersand Ground Penetrating Radar(GPR), so pipeline inspection technology is invented.Based on MFL technology,3D low-power MFL inspection probe and data accesssystem are designed to detect pipeline corrosion. The defect recognition model of3DMFL detection is established by artificial defect experiments. We utilize the eddy currenteffect to design the ID/OD probe for ID/OD identification which is placed along the3DMFL probe. Thus we can collect both inner and outer defect signal at one time, achievingfull coverage of pipeline circumferential information by array mode. Based onquantitative identification algorithm for3D defect parameters, we can calculate thedefect length, width and depth with the accuracy of±2.1%,±3.5%and±6%. Operatingmode of ‘power-supply by times, sampling by turns’ successfully solves the powerconsumption problem.In this article,3D-MFL magnetic field is analyzed, laying the foundation for pipelinemagnetization device and3D-MFL detection. The power-consumption problem ofinspection equipment is successfully solved by3D low-power MFL inspection probe.The problem of calibration for3D MFL inspection and defect identification precision issolved by defects quantitative identification algorithm we proposed. The work done inthis article establishes the technical foundation of the industrial applications for3D MFLcorrosion-detection devices work in pipelines.