A High-Voltage Short-Burst Electroacoustic Measurement Method for Piezoelectric Acoustic Logging Transmitters.

Piezoelectric acoustic logging transmitters are commonly evaluated using low-voltage small-signal impedance measurements, whereas their practical operation involves high-voltage, high-current, finite-cycle short-burst excitation. This difference makes it difficult to predict the actual loaded electrical input state and directional acoustic response from conventional impedance spectra alone. In this study, a high-voltage short-burst electroacoustic measurement method is developed for piezoelectric acoustic logging transmitters. Unlike conventional small-signal impedance analysis, the proposed method synchronously measures the terminal voltage, terminal current, and 1 m hydrophone response under the same high-voltage short-burst excitation condition. A three-cycle sinusoidal burst was amplified and applied to a water-loaded PZT-5A tube transducer over an 8-100 kHz frequency sweep. For the finite-cycle non-steady-state waveforms, adaptive time-window extraction and single-frequency projection were used to obtain the dynamic apparent impedance, instantaneous power, single-burst input energy, effective short-burst transmitting voltage response, and hydrophone direct-wave voltage energy. The results show that small-signal impedance spectra measured in air and water can identify modal characteristics and candidate frequency bands, but they cannot directly represent the actual high-voltage short-burst operating state. The single-burst input energy shows a stronger frequency-dependent association with the hydrophone direct-wave voltage energy than the impedance magnitude or current amplitude alone. To further evaluate practical applicability, eight nominally identical acoustic logging transmitters were characterized using both conventional small-signal impedance analysis and the proposed high-voltage short-burst method, and their transmitting performances were independently evaluated in a natural-rock model well. The high-voltage dynamic conductance and, in particular, the single-burst input energy showed substantially stronger correspondence with the received P-wave voltage energy than the conventional small-signal conductance. The proposed method provides a practical measurement basis for evaluating acoustic logging transmitters under realistic short-burst excitation conditions, while the eight-transmitter model-well experiment provides preliminary support for its potential use in transmitter screening.