圆柱形压电换能器的测井声场有限元仿真

Finite element simulation of well logging acoustic field of cylindrical piezoelectric transducer

为了研究圆柱形压电换能器测井声场特性,该文采用有限元ABAQUS中动力学隐式算法和动力显式算法相结合的方法,借由压电单元、声学接触单元及无限单元解决了压电耦合、流固耦合及截断返回(波)问题,建立了圆柱形压电换能器的声波测井有限元-无限元耦合分析模型,通过重启动分析方法,完成了对整个声波测井过程的仿真分析。结果表明,通过与有限差分法结合完全匹配层(PML)的算法对比,该文建立的声波测井有限元-无限元耦合分析模型在解决测井声场分析问题上具有较高的可靠性。在激励电压作用下,于井轴接收到的返回波的声压量级衰减严重,而测井环境中的流体介质密度、固体介质密度对于井轴接收到的返回波的声压量级衰减影响较小。

In order to study the well logging acoustic field characteristics of the cylindrical piezoelectric transducer,a coupling analysis model of well logging finite element-infinite element is established by using the method of combining dynamic implicit algorithm and dynamic explicit algorithm in ABAQUS.The simulation analysis of the entire well logging process is completed by the restarting analysis method.The results show that the established well logging finite element-infinite element coupling analysis model has high reliability in solving the problem of well logging acoustic field analysis by comparing with the finite difference method combined with the perfectly matched layer(PML)algorithm.Under the action of the normal excitation voltage,the acoustic pressure level of the return wave received on the shaft is attenuated seriously.The density of the fluid or the density of the solid in the well logging environment has little effect on the attenuation of the acoustic pressure level received on the well axis.