Abstract:
The requirements of acoustic logging on the detection distance and detection accuracy of the instrument are constantly improving. The traditional pulse square wave excitation method only excites the acoustic energy near the resonant frequency of the transducer, which is difficult to meet the field needs such as low-frequency excitation. This paper designs a sine wave wide frequency excitation circuit based on push-pull power amplification technology to achieve accurate adjustment of the transducer excitation frequency, and designs a signal amplification and rectification circuit to optimize the sine excitation signal. In addition, the performance of the excitation circuit is seriously affected by the environment such as temperature and pressure during the downhole operation of acoustic logging tools. In order to keep the excitation energy constant, this paper designs a power adaptive adjustment technology based on PID control. The experimental results show that the excitation circuit can realize wide frequency high-power and adaptive sine wave excitation. Applying this circuit to downhole instruments can significantly improve the excitation performance, improve the detection distance and resolution of instruments, and promote the exploration and development of oil and gas fields.