Research On Motion Compensation Method Of Underground TEM Array Detection System

In recent years,in the process of oil and gas resources exploitation,casing damage causes many oil and gas wells to be scrapped,shut in and shut down,which seriously affects the oil recovery.Transient electromagnetic casing damage detection technology has been widely used in the field of oil and gas well casing damage detection because of its time domain diffusion characteristics of transient impulse response.It can timely check the casing damage and provide a real and powerful basis for casing repair.However,the movement measurement method of downhole transient electromagnetic array side detection system will affect the detection performance.Based on the transient electromagnetic detection technology,this paper focuses on the motion compensation method of transient electromagnetic array detection system.Firstly,based on the principle of transient electromagnetic casing damage detection,this paper establishes a non-uniform multi-layer cylindrical logging model,analyzes the frequency domain and time domain response signals of electromagnetic probe in cased well,and introduces the structure of transient electromagnetic array detection system,studies the casing damage location method based on array eccentric probe,and corrects the transient electromagnetic logging data to eliminate the influence of abnormal data,probe offset and temperature drift on logging data.On this basis,the influence of the receiving and transmitting distance on the detection signal in the dynamic measurement process of the transient electromagnetic array detection system is studied,and the receiving and transmitting distance compensation method of the transient electromagnetic detection signal is proposed,which can realize the receiving and transmitting distance compensation of the detection signal by establishing the compensation coefficient matrix.In addition,aiming at the problem of circumferential rotation of the instrument,the influence of rotation on casing damage location of eccentric probe is studied,and a casing damage location correction method based on MEMS gyroscope is proposed.According to the motion compensation method of the transient electromagnetic array detection system,the system framework is built,the appropriate parameters of the device are selected,and the corresponding functional circuit is designed.The MEMS gyroscope is used to obtain the rotation angle of the instrument,correct the three-dimensional coordinates of the data,and realize the accurate location of casing damage.Finally,based on the transient electromagnetic array detection motion compensation system,a large number of indoor and outdoor experiments and field experiments are carried out.The experimental results show that the proposed method can effectively improve the detection performance of TEM system and improve the accuracy of casing damage location.