Design Of Underground Acquisition Circuit For Quadrupole Acoustic Logging Tool While Drilling

With the development and prosperity of today's society,the consumption and demand of petroleum energy have grown rapidly.Oil is the key to development of the country.Research and development of advanced logging instruments have great significance for improving the level of oil exploration,increasing oil production,and ensuring national energy strategy security.The logging while drilling quadrupole sonic logging tool is a logging instrument with high application value.The sonic logging while drilling is an important branch of petroleum logging technology.Compared with the traditional cable logging technology,and the measured information can more accurately reflect the formation characteristics and has a greater advantage.This thesis focuses on the hardware circuit design and program design of the acquisition circuit of the Drilling Quadrupole Acoustic Logging Tool.The purpose of the hardware circuit is to process the signal output from the acoustic transducer,mainly including the signal conditioning circuit,the signal acquisition circuit,the signal acquisition control circuit,and the communication interface circuit.The thesis describes the design process of the low-noise analog signal conditioning circuit,and the signal conditioning circuit.There are a plurality of functional modules,including a signal receiving circuit,a differential amplifying circuit,a program-controlled amplifying circuit,a band-pass filtering circuit,and an ADC driving circuit,which can realize amplification and filtering of a weak acoustic wave signal.The signal acquisition circuit and the signal acquisition control circuit adopt a combination of ADC+MCU to convert the conditioned acoustic analog signal into a digital signal that is easy to transmit and store.The communication interface circuit adopts the serial differential method to realize high-speed transmission of logging data and can effectively reduce the interference of common mode noise during data transmission.The program is the basis of the normal operation of the hardware circuit.The acquisition of logging data is completed by the PC-based PC software.The thesis designs the communication protocol between the underground acquisition circuit and the main control circuit,realizes the control and data processing of the ADC acquisition process,and describes in detail.A remote online download method for a single-chip computer program to avoid frequent disassembly during instrument upgrade.Finally,this thesis lists the corresponding single board debugging and system joint adjustment process of the underground acquisition circuit,and gives the debugging process,results and analysis,indicating that the logging instrument meets various design indicators.