Acoustic logging phased arc array and its radiation directivity
声波测井相控圆弧阵及其辐射指向性

A kind of acoustic phased arc array with circumferentially controlled directivity presented in this paper can be used to make acoustic logging with circumferential azimuth detection function.The arc array transmitter is composed of many ceramic flexural vibrators which are arranged in an annulus.Directional radiation is realized by controlling the vibrating phase of each vibrator.The radiation directivity and its relation with the parameters of a self-made 28-element phased arc array,such as the number of active element and frequency,are investigated by numerical simulation and experimental measurement.The results of numerical simulation and experimental measurement have good agreement.The directivity of the arc array becomes better with the increasing of the number of active element and acoustic frequency.Unlike monopole,dipole and quadrupole transmitters presently used in acoustic logging,the acoustic phased arc array,which will be used downhole in the future,is the key to realize acoustic logging with circumferential azimuth detection function and has a good application prospect in the petroleum industry for anisotropy evaluation,directional drilling and crosswell formation evaluation and so on.