Research On Nondestructive Testing System Of Coiled Tubing Defects Based On The Principle Of Rotating Electromagnetic Field

Coiled tubing is an indispensable tool in oil exploitation and plays an important role in oil exploitation.Its quality will have a direct effect on the smooth production of oil fields.The industry’s demand for nondestructive testing methods to ensure the safety of coiled tubing in production and use is increasing day by day.In view of the above problems,this paper studies the key problems of the application of rotating electromagnetic field NDT technology in the NDT of coiled tubing.Firstly,based on the traditional eddy current detection principle,the rotating electromagnetic field detection principle is studied and analyzed,and the theoretical model of rotating electromagnetic field detection is proposed.Secondly,in the simulation,the finite element model of the rotating electromagnetic field used in the defect detection of the coiled tubing was established,and the sensor parameters were designed and optimized for the interference factors on the production site,and the on detection system of the coiled tubing was built based on the principle of the rotating electromagnetic field nondestructive detection.Finally,based on the theory and simulation testing research,the coiled tubing with defects is tested.The test results show that the rotating electromagnetic field nondestructive testing system can be used to detect the defect of coiled tubing.The paper mainly carries on the concrete research from the following four aspects:(1)Theoretical Study on Nondestructive Testing Technology of Rotating Electromagnetic FieldTraditional eddy current testing theory are introduced,and based on the principle of the eddy current detecting principle of rotating electromagnetic field detection for this paper,rotating electromagnetic field was studied in the absence of defects and defect with coiled tubing surface of magnetic field and eddy current distribution,analyzes the defects caused by the mechanism of magnetic field perturbation,for subsequent coiled tubing detection based on rotating electromagnetic field to provide theoretical basis.(2)Simulation of structural parameters of rotating field probe based on receiving coilIntroduced based on the principle of receiver coil rotating field probe defect detection,according to the theory of electromagnetic field modeling in COMSOL MULTIPHYSICS based on receiving coil rotating field in the probe used in the coiled tubing defect detection model,probes the parameters of the receiving coil is studied and the relationship between the simulation results,and according to the testing requirements to probe the structural parameters optimization design was carried out.(3)The construction and test research of coiled tubing on-line inspection system based on rotating electromagnetic fieldAccording to the principle of rotating electromagnetic field nondestructive testing,the requirement of tubing defect detection and the field conditions,the rotating field probe was prelimatively designed and manufactured by using Solid Works modeling software.The software of rotating electromagnetic field space magnetic field imaging and defect visualization is developed by using Lab VIEW software,which can realize the functions of parameter setting and signal debugging,signal analysis and defect contour display,etc.To prepare test blocks of various types of defective coiled tubing,design the test scheme,carry out relevant experimental research under laboratory conditions,and compare and analyze the test results with the simulation results.(4)Openable rotary field probe based on fitted receiving coilAccording to characteristics of coiled tubing field work and testing requirements,designed and developed based on the joint of the coil can be open type rotating field probe,the parameters of the joint structure of the coil simulation research,put forward the open type rotating field probe excitation device and joint type of receiver coil design,and under laboratory conditions were studied.The probe can realize the disassembly and assembly function to meet the special requirements of coiled tubing testing and improve the efficiency of field testing.The open rotary field probe is very important for the nondestructive testing of coiled tubing.