Design of downhole ultrasonic flow measurement based on CTMU technology

The majority of existing downhole ultrasonic flow measurement devices rely on special integrated chips to measure and then calculate flow rate via a microcontroller. However, the complicated circuit design is the Achilles' heel of this scheme. The present study focuses on the complex circuit problem. Here, a dsPIC33EV is proposed as the master chip of the time difference ultrasonic flow measurement system, and then the time is precisely measured by the Charge Time Measurement Unit (CTMU) module inside the master chip. We further reveal the structure and principle of CTMU, system design flow, and ultrasonic receiving circuit. The scheme is believed to be a design that simplifies the hardware circuit of the downhole ultrasonic flow measurement system and reduces the PCB space. In addition, the miniaturized downhole flow measurement circuit also makes downhole flow measurement more convenient.