横波远探测测井换能器研究

为提高偶极子横波远探测反射波的信噪比和增加其探测距离，根据偶极子井孔模式波的激发特性及反射波传播特征分析，研制了基于三叠片的低频大功率偶极子的横波远探测换能器，以降低模式波的相对能量和增加反射波的相对能量。为了得到满足要求的低频大功率偶极换能器，采用有限元方法对现有三叠片进行了优化改进，得到一种符合设计要求的换能器结构，最后制作了样机并对其进行了测试。样机测试结果跟仿真吻合得很好，低频性能得到了极大改善：换能器在谐振频率1.2 kHz附近具有极好的偶极子指向性，谐振频率处的响应比X-MAC同频率段大19 dB。该换能器的研发成功将为偶极子远探测测井仪器性能及成像质量的提高奠定了坚实的基础。

Investigation of acoustic reflection imaging logging transducer

In order to increase signal-to-noise ratio and improve detection range of shear wave reflection imaging, a low-frequency high-power dipole transducer based on trilaminar bender bars is developed according to the analysis of excitation characteristics of dipole borehole mode and propagation characteristics of reflection wave to reduce relative energy of mode waves and increase the relative energy of reflection waves. To meet the demands of low-frequency, high-power, dipole radiation, finite element method is adopted to optimize the trilaminar bender bars structure and then get a transducer structure comply with the design requirements. Finally, a prototype is manufactured and tested in air and in oil tank. The test results show that the resonant frequency is about 1.2 kHz with an excellent dipole directivity pattern and the frequency response is 19 dB larger than X-MAC transducer at this frequency. The test results meet simulation very well, which proves the correctness of simulation method. The success of R&D of this transducer lays a solid foundation for the improvement of sonic reflection imaging logging performance and imaging quality.