Research On Low Power Consumption Miniaturized Downhole Ultrasonic Flow Measurement System

Ultrasonic flowmeters are widely used in downhole oil measurement and analysis because they are non-contact,easy to install and do not change fluid motion.However,the time difference ultrasonic flowmeter,which takes GP21 as the time measuring chip,has the disadvantages of too many hardware circuit modules and relatively high power consumption when measuring downhole flow.To solve this problem,a low power consumption miniaturized ultrasonic flowmeter is designed in this dissertation.Firstly,ultrasonic flow measurement based on time difference method is studied.The low power chip ds PIC33 EV is used as the main control chip of the system.The charging time measuring unit(CTMU)is used to measure the forward and reverse flow time of ultrasonic wave propagation in the fluid.According to the selection of low power chip and the principle of CTMU technology to measure time,the hardware circuit control module of downhole ultrasonic flow measurement system and ultrasonic time measurement module based on CTMU are designed.The results show that the design uses one chip to realize the functions of two circuit modules at the same time,which can effectively improve the power consumption of the system and reduce the hardware circuit modules.On this basis,based on the propagation characteristics of ultrasonic wave,and on the premise of low power consumption and miniaturization requirements,the ultrasonic signal driving circuit,receiving amplifier circuit and signal conditioning circuit are designed.Using AD software,the circuit diagram of underground measurement hardware is drawn,and PCB is welded.In addition,a data storage and transmission circuit is designed to solve the problem that the flow meter is not easy to check the measured data at any time during the ultrasonic flow measurement.Lab VIEW software is used to design the upper computer processing system,and the measurement data is transmitted to the upper computer for data processing.According to the selected chip parameters and performance,the corresponding software program is designed,and the designed circuit module is debugged.Finally,through the establishment of an indoor test platform and repeated test measurement,the results confirm that the ultrasonic flowmeter designed in this paper has the performance of low power consumption and miniaturization.Moreover,the measurement system has high stability and accuracy,which is of great significance for the follow-up research.