基于1−3型压电复合材料的超声测井换能器研究

Research on 1-3 Piezocomposite Ultrasonic Logging Transducer

  • 摘要: 针对超声成像测井中PZT压电换能器存在频带窄、灵敏度低等缺点,以PZT−5A压电陶瓷为压电相、环氧树脂为聚合物相,理论分析了压电相体积百分比对1−3型压电复合材等效性能参数的影响。仿真分析不同结构尺寸换能器的谐波响应特性,最终确定了1−3型压电复合材料超声测井换能器参数,并采用实验手段测试其谐波和脉冲响应特性。结果表明,换能器的中心频率为319.82 kHz,相对脉冲回波灵敏度为−26.64 dB,脉冲宽度为6.67 μs,−3 dB相对带宽为50.38%,换能器可有效激励厚度振动模式,产生幅度大而脉宽窄的脉冲回波。研究结果验证了该超声测井换能器灵敏度高、频带宽,可有效拓展工作频带,提高复杂测井环境下的成像质量,在超声成像测井现有仪器升级改造和新一代仪器研制中具有应用价值。

     

    Abstract: 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.

     

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