Research On The Ultrasonic Imaging Logging Instrumnet

Ultrasonic borehole imaging instrument uses the echo signal of wellbore for scanning imaging. It uses a ultrasonic transducer for transmitting and receiving ultrasonic signals, and the corresponding processing circuit to extracts the effective borehole information. The signal is sent to the PC for processing and displaying in order to detect lining corrosion and the damage state. The logging instrument is mainly designed for the wellbore. The logging system is stable and reliable, with high practical value and reference.The paper introduces the borehole imaging logging instrument of the basic imaging principle. It introduces the design of hardware circuit and control software. The design principle of various circuit and method are introduced on the part of circuit simulation analysis. The hardware circuit includes ultrasonic excitation emission circuit, ultrasonic amplitude limiting circuit, ultrasonic amplifying and filtering circuit, detection circuit, A/D circuit, FIFO circuit, SCM control circuit and interface circuit. The interface circuit is the single core cable 2ASK current modulation. The software part comprises a controlled procedure design and ultrasound software interface design. Hardware circuit mainly adopts the MCU to control the emission circuit of ultrasonic transducer for driving, and controls the A/D to convert the ultrasonic analog echo information. At the same time, it controls the FIFO to cache the echo information. Then the information is transmitted to the PC machine through the interface circuit. The control program and interface software is Keil C and C#.NET.The circuit of logging instrument is verified by the experiment, obtaining good excitation pulse, extracting the ideal weak echo signal. The PC machine can obtain a good image. It has good detection effect to small diameter wellbore and makes very high reference value on ultrasonic logging study.