The Research On Multi-parameter Acquisition System Of The Acoustic Tool Using Dual Sources With Opposite Polarity

Due to the serious interference of the casing wave in the measurement of formation wave,there has not been any major breakthrough in the casing acoustic logging for a long time.The theory of dual sources with opposite polarity is a new technology that's been developed in recent years.It is aimed to suppress casing wave on the data acquisition,improve the signal to noise ratio.Preliminary results have been obtained from the experimental prototype and also the longitudinal wave time difference of the formation wave.However,the study shows that the technology is greatly influenced by the consistency of the two sources.According to the convolution process about the theory of acoustic propagation,using the deconvolution method to improve the consistency of sound source,can further suppress of the casing wave.In order to achieve the purpose of enhancing the effect of the suppression based on the feedback to the control system after receiving waveform processing,a multi-parameter parallel acquisition system is designed.It can receive the acoustic signals,environmental temperature,pressure and acoustic excitation signals by the acoustic array logging and also preliminary experimental studies were carried out.The acquisition system mainly includes the signal conditioning module pre and processing module,a pre-module is mainly to transmit the acoustic analog signals,ambient temperature and pressure signals attenuation,filtering and amplification processing,processing module through the analog signals into digital signals for further processing,and finally integrated information uploaded to the ground system.In this paper,the signal conditioning module pre and processing module of the acoustic tool using dual sources with opposite polarity is described in detail.The first chapter mainly introduces the principle of the technology,domestic and foreign dynamics and research contents.The second chapter introduces the overall structure of acoustic logging instrument and the general scheme design of collecting system.The third chapter focuses on the design of the conditioning module pre circuit and temperature pressure information collection module.In the fourth chapter,the design of underground signal digital transformation and data processing circuit is introduced,and then the detailed module design of this part of the circuit is further elaborated.The fifth chapter lists the experimental results obtained by testing the system in a specific experimental environment.The last chapter summarizes the full text.