Design And Experimental Research Of Ultra HD Oil And Gas Pipeline Magnetic Flux Leakage Internal Detection Probe

In recent years,the laying mileage of oil and gas pipelines in my country has increased significantly.However,with the increase of pipeline operation time and the joint action of internal media and external environment,the corrosion of oil and gas pipelines has become more and more serious,which affects the pipeline.The longevity of this product even threatens production and life safety.Therefore,regular monitoring of pipeline corrosion,timely detection and resolution of problems,and reduction of accidents have become the main concerns of enterprises and inspection personnel.With the continuous progress of computer technology,data processing and analysis technology,the current magnetic flux leakage detector has gradually developed from the traditional one-dimensional sensor to the three-dimensional ultra-high-definition detection technology.The three-axis ultra-high-definition sensor can simultaneously record the threedimensional component of the leakage magnetic field.Improve the ability to identify the location,size and type of pipeline defects and detection accuracy.The probe is an important structure to realize ultra-high-definition magnetic flux leakage detection,and the magnetic field signal collected by the sensor will be affected by many factors.Therefore,it is necessary to simulate and analyze the pipeline magnetic flux leakage detection.The simulation result will also be used for the subsequent probe structure design And the formulation of the experimental program provides a sufficient theoretical basis.Therefore,this paper adopts a combination of theoretical analysis and experiment,and uses finite element software to establish a pipeline magnetic flux leakage internal detection analysis model.Taking a representative hemispherical corrosion defect as an example,using the controlled variable method,by changing the sensor lift-off value,Magnetization structure air gap value,defect volume,magnet length,distance between two magnets,inner and outer wall defects,relative position of the two defects and other single variables,studied the influence of various factors on the spatial distribution characteristics of pipeline defect leakage magnetic field,and perforated oil and gas pipelines The problem has been analyzed and researched.On the basis of theoretical research and finite element analysis of pipeline magnetic flux leakage internal detection,combined with the structural characteristics of oil and gas pipelines and detectors,the probe structure of pipeline magnetic flux leakage internal detector is designed,and the three-axis ultra-high-definition magnetic flux leakage sensor is used to detect pipeline defects High-resolution detection is performed,and eddy current sensors are used as auxiliary sensors to detect defects on the inner wall of the pipeline,which makes up for the lack of magnetic flux leakage sensors in identifying defects on the inner and outer walls.The specimens with artificial defects were prepared and tested under laboratory conditions to verify part of the finite element analysis results.The experimental results show: The probe structure designed in this paper can effectively detect the leakage magnetic field signals in the axial,radial and circumferential directions of the pipeline.The voltage signal amplitude of the leakage magnetic field also increases with the increase of the depth of the defect,and it can accurately identify the inside of the pipeline.Outer wall defects,the detection effect of the probe structure on pipeline defects meets the expected target requirements,and realizes ultra-high definition detection of pipeline defects.