Simulation And Design Of The Acoustic Telemetry Piezoelectric Transducer Based On The Finite Element Method

The acoustic telemetry of the measure is install the transducer under the oil well,it stimulates the tubing string to produce longitudinal vibrations,it makes acoustical signal as the carrier of message,tubing string as the channel of sound wave,it makes the message under the well transfer to the wireless transmission technology on the ground.This technique gains attention at home and abroad for it's low cost,easy to operate,and it can also achieve real-time transmission.This article according to the foundation of piezoelectric transducer,and the application in acoustic logging,using COMSOL Multiphysics,designed the acoustic telemetry piezoelectric transducer.Through theoretical analysis and the result of the simulation of the eigenfrequency of stackable transducer,proved the reliability using finite element software analysis transducer's performance in acoustics.Afterwards,build the theoretical model of acoustic telemetry transducer,through simulated analysis get the rules of piezoelectric transducer's structure and the change of material to eigenfrequency.Through transducer theoretical mode at last stages' resonant mode,get the conclusion of transducer at the first stage resonant mode is the best mode of vibration,the research has some significance to improve the transducer's acoustic performance.Build combination of acoustic telemetry transducer and solid sound field's finite element,through simulated analysis,research the response frequency character of acoustic telemetry,get the conclusion of transducer's working frequency is itself acoustic performance when the resnonant frequency.Influence of acoustic performance on the selection of inspection transducer piezoelectric element structure and piezoelectric materials is the components of the piezoelectric ceramic transducer piezoelectric element by axial direction of polarization 10 groups stacked on the contrary,the piezoelectric material of piezoelectric PZT-4.Under the premise of ensuring the working frequency of the transducer is invariable,the structure of the transducer is optimized.The simulation results show that the increase of the contact area between the transducer and the tubing string and the structure of the hollow tapered diameter converter can improve the acoustic impedance matching of the transducer and increase the transmitting power of the transducer.In this paper,the overall structure of the transducer is optimized,and the acoustic transducer with low frequency and high power can be transmitted.