可用于声波测井的相控圆弧阵声波辐射器  

A Kind of Acoustic Logging with Phased Arc Array Transducer

作　　者：乔文孝[1] 鞠晓东[1] 车小花[1] 

机构地区：[1]中国石油大学油气资源与探测国家重点实验室,北京102249

出　　处：《测井技术》2009年第1期22-25,共4页Well Logging Technology

基　　金：国家自然科学基金重点项目(10534040);面上项目(40574049和40874097);高等学校博士学科点专项科研基金(课题编号:20070425028)

摘　　要：为了使声波测井具有周向探测能力,提出了可应用于声波测井的、具有周向辐射特性的相控圆弧阵声波辐射器方案。这种声波测井圆弧阵声波辐射器由多个压电振子沿着圆周排列。研究表明,通过控制各个振子的激励时间可以实现向某个方位方向的声波辐射。在声波测井频率范围内,随着工作阵元个数的增加,圆弧阵辐射声波的周向指向性增强。在井下采用相控圆弧阵作为声波辐射器可以真正实现方位声波测井,这种声波辐射器在各向异性地层评价、定向钻井等石油工程中有良好的应用前景。The acoustic monopole source, widely used in acoustic well logging, can be seen approximately as a point source. The acoustic field generated by the point source is mono-directional. Unlike the monopole source, the dipole and quadrupole sources are directional, but their azimuthal measurement ability is limited and they have multi-solutions in formation information inversion. Azimuthal acoustic logging is urgently required in complicated petroleum and gas reservoir exploration. The key technique that the acoustic well logging has azimuthal measurement ability is to develop a kind of downhole source which can radiate acoustic energy azimuthally. In this paper, a kind of acoustic phased arc array transmitter is presented. The arc array transmitter is composed of many ceramic flexural vibrators which are arranged in an annulus. Acoustic field generated by the phased arc array is calculated by the finite difference method. Unlike monopole, dipole and quadrupole transmitters, directional radiation is realized with the phased arc array by controlling the vibrating phase of each vibrator. It means that azimuthal measurement for acoustic logging can be realized by using this kind of phased arc array. The directivity of the arc array becomes better with increase of the number of active element, that is clearly shown with the 3dB band width of main lobe. The acoustic phased arc array, which will be used downhole in the future, is the key for azimuthal acoustic well logging which plays good application foreground in the petroleum engineerings of anisotropy evaluation, directional drilling and so on.

关 键 词：声波测井 换能器 相控线阵 圆弧阵 指向性 方位 

分 类 号：P631.814[天文地球—地质矿产勘探]