Borehole acoustic logging system having automatic reflection signal level control

摘要

A borehole televiewer employs a transducer energized by repetitive voltage pulses for generating pulses of acoustic energy for transmission to the walls of a borehole and for detecting direct reflections of acoustic energy from the borehole walls. A detector converts the acoustic energy reflections into reflection signals. Those reflection signals are applied along with a reference signal representing a desired constant level for the peak amplitude of the reflection signals to an error amplifier. The output of the error amplifier controls the voltage pulses utilized to energize the transducer so as to maintain a constant level of peak amplitude for the reflection signals produced from the detected acoustic energy direction reflections from the borehole wall.