Research on 1-3 Piezocomposite Ultrasonic Logging Transducer

To overcome the limitations of narrow bandwidth and low sensitivity of PZT piezoelectric transducers used in ultrasonic imaging logging, proposed was a research scheme for designing and manufacturing ultrasonic logging transducer using 1-3 piezocomposite as the energy conversion component. The 1-3 piezocomposite consists of PZT-5A piezoelectric ceramic as the piezoelectric phase and epoxy resin as the polymer phase. The influence of the volume percentage of the piezoelectric phase on the equivalent performance parameters of the piezoelectric composite was theoretically analyzed. Different structural dimensions were selected to simulate and analyze the harmonic response characteristics of the transducer, and the structural parameters were determined to develop an ultrasonic logging transducer. Experimental methods were used to test the harmonic and pulse response characteristics of the transducer. The results show that the transducer has a center frequency of 319.82 kHz, a relative pulse-echo sensitivity of −26.64 dB, a pulse width of 6.67 μs, and a −3 dB relative bandwidth of 50.38%. The transducer can effectively excite the thickness vibration mode, generating pulse echoes with large amplitude and narrow pulse width. These findings demonstrate that ultrasonic logging transducer based on 1-3 piezocomposite exhibits high sensitivity and wide bandwidth characteristics, effectively extending the operational frequency range and improving imaging quality in complex logging environments. It holds significant application value for upgrading existing tools and developing new-generation equipment of ultrasonic imaging logging.