超声反射成像测井的有限元分析  

The finite element analysis of ultrasonic reflection method used in acoustic logging

作　　者：孙志峰[1] 陈洪海[1] 刘西恩[1] 

机构地区：[1]中海油田服务股份有限公司,北京101149

出　　处：《应用声学》2013年第6期495-500,共6页Journal of Applied Acoustics

基　　金：国家科技重大专项(2011ZX05020-005);国家863资助项目(SQ2010AA0920229001)

摘　　要：利用有限元方法研究了有限长换能器激发的超声波在套管井多层介质中的传播规律。数值模拟了换能器长度及套管曲率对反射回波的影响。随着换能器长度增加,反射回波频谱谱陷个数由单一向多个变化;套管共振透射窗的反射波相对能量先逐渐减小后振荡变化,较小长度的换能器对套管与水泥环界面的声阻抗区分能力优于较大长度的换能器。随着套管曲率的增大,套管共振透射窗的反射波由单一模式的厚度振动纵波向其他模式波变化。数值模拟结果对超声脉冲反射声波测井仪器的换能器结构优化设计起到了良好的指导作用。Acoustic field of plane ultrasonic transducer was analyzed in multilayer medium in casing well using the finite element method. The influence of the length of transducer and the casing curvature on ultrasonic pulse echo was simulated numerically. As the length of transducer increases, the number of leakage peak of frequency spectrum changes from single to multiple. The relatix^e energy of reflection wave within the window of resonant transmission decreases firstly and then oscillates. The discriminatory ability of acoustic impedance in small transducer is much better than that in the large one. As the casing curvature increases, reflection wave within the window of resonant transmission changes from a single mode to other modes. Numerical simulation results serve as a good guidance on the optimization design of ultrasonic transducer.

关 键 词：超声反射 频谱 套管曲率 有限元分析 声波测井 

分 类 号：P631.8[天文地球—地质矿产勘探]