Research On Oil Pipe Hoop Position Detection Method In Workover Operation Based On Electromagnetic Sensing Technology

In the process of oil and gas exploration and production,workover operations are crucial.However,the task has become increasingly challenging,with high labor intensity.To improve workover efficiency and reduce labor intensity,there is a need for a higher degree of automation.The first step towards this goal is to automatically detect the position of tubing couplings Accurately detecting and controlling the position of tubing couplings is essential for the safe operation of oil workover machines.In order to achieve the full automation of the operation platform the tubing coupling position relative to the position of the hydraulic tongs decides whether the tubing string can be coupled or decoupled.How to accurately detect and control the position of the tubing coupling is very important to the safe operation of oil workover machines.This paper proposes a method of detecting and identifying the tubing coupling based on electromagnetic testing technology.A tubing coupling detector is designed with 3 coils a primary coil or excitation coil and then 2 secondary coils(detection coils)that are differentially connected to detect the output induced voltage,a signal processing circuit is designed and experimental study on the performance and reliability of this technology is studied.Major research work includes the following aspects:Firstly,a theoretical analysis of the tubing coupling detection principle and its feasibility were determined.Secondly,Ansys Maxwell software is used to design,simulate and analyze various physical parameters influence on the induced output signal of the tubing coupling detection device.These parameters include the number of turns of the coils,excitation frequency etc.According to the simulation results and the practical conditions of the workover operations,proper parameters of the detector were selected and conducted simulation experiments,The experiment data shows that the finite element simulation results are believable,and prove that the coupling detection scheme is feasible.Finally,to deal with the complicated electromagnetic signal of the tubing coupling detection device,a set of circuit system fit with the transducer was designed.The excitation circuit and power-following circuit for the primary coil are designed.Using the signal processing chip AD698,the processing circuit of detected differential output signal was designed,completing the function of signal recognition,computation and filtering.In addition,according to the electrical requirements of the transducer,the relevant integrated stabilized voltage supply circuit,the differential following circuit for amplifying the excitation power,and the phase adjustment circuit to improve the detection trigger precision,were also designed.According to the simulation results and the practical conditions of snubbing operation we choose the proper parameters of the detector,in accordance with the selected parameters of detection coil and conducted simulation experiments,The experiment data show that the finite element simulation results are believable,and prove that the coupling detection scheme is feasible.