新一代声波测井技术采用了相控圆弧阵作为声波辐射器,构成圆弧阵的压电振子的耐高温性能一致性是一项重要的技术指标。以相控圆弧阵所使用的阵元为例实验研究了压电振子的耐高温性能以及阻抗特性一致性随温度的变化。测试结果表明,压电振子的谐振频率和静态电容随着温度的升高而增大,而最大电导和脉冲响应幅度随着温度的升高而降低;压电振子的阻抗特性一致性随着温度的升高相对下降,150℃下相对变化量可控制在4%以内。将压电振子从高温环境冷却至常温27℃后,压电振子的阻抗特性具有可恢复性。经测试的压电振子的耐温指标能够达到150℃左右,且高温下阻抗特性一致性较好,能够满足井下高温环境的应用要求。
Since the acoustic phased arc array transmitter is used in the latest generation acoustic logging, the temperature-resistant consistency of benders which are employed to form arc array transmitter has become a key technical index. High temperature resistance and impedance charac- teristics consistency of benders, which vary with temperature, are investigated by experiments. Experimental results show that, as the temperature rises, the resonance frequency and shunt capacitance increase, but the maximum conductance and impulse response magnitude decrease. The relative variation is not greater than 4% in 150 ℃ although impedance characteristics consistency decrease slightly. With the temperature reducing to 27 ℃, impedance characteristics of benders are restorable. Finally, it is considered that the temperature index of benders tested can reach around 150 ℃, and they maintain relative good impedance characteristics consistency in high temperature, which fully satisfies application demands of downhole high temperature environment.