Research On Magnetic-acoustic Coupling Acoustic Signal Detection And Processing Technology

Magneto-acoustic coupling technology is a new type of conductivity imaging technology.By applying static magnetic field and alternating magnetic field,the acoustic signal is excited in the conductive medium.The acoustic signal detected by the sensor contains the conductivity information of the measured medium,but the excitation The generated acoustic signal is extremely weak,which brings great difficulty to the detection of the signal.Therefore,this article takes oil well produced fluid as the measurement object,explores the water cut measurement method of oilwater two-phase flow based on magneto-acoustic coupling,and develops the key technology research of magnetoacoustic signal detection and processing.In this paper,the working principle of magneto-acoustic coupling is analyzed.On this basis,the feasibility of measuring oil-water two-phase flow based on the magneto-acoustic coupling technology is discussed.With the help of COMSOL Multiphysics multiphysics simulation software,the water cut measurement model is constructed,and the pure oil/ Three different media of oil-water mixture/pure water are simulated and studied,and the static magnetic field,alternating magnetic field,and acoustic sensor position are optimized according to the simulation results.Optimizing high-sensitivity acoustic wave probes,using lock-in amplifiers to amplify weak signals;developing an ARM-based multi-channel weak signal data acquisition system to achieve weak signal detection;studying magnetoacoustic signal processing methods,including data normalization Improve the signal-to-noise ratio of the detected signal.An indoor test system was constructed to detect the excited acoustic signals with pure oil/oil-water mixture/pure water respectively to verify the reliability of the multi-channel weak signal acquisition system and the effectiveness of signal processing.Through experiments,the results show that the developed lockin amplifier works reliably and can effectively amplify weak magnetoacoustic signals.The performance of the multi-channel weak signal acquisition system is stable.After signal processing,the signal-to-noise ratio is significantly improved.The research on the core technology of magneto-acoustic coupling technology,and its results lay the foundation for the application of magneto-acoustic coupling technology.