声波测井相控线阵辐射器幅度加权的实验研究

在声波测井工程中使用相控线阵声波辐射器可以使声波向着接收探头一侧辐射,从而提高声波测井的信噪比和探测距离.对相控线阵进行幅度加权可以改变其辐射主瓣的角宽,这种技术在声波测井中有良好的应用前景.推导了幅度加权条件下相控线阵声波辐射器的指向性函数,研究了利用幅度加权方法增加和减小相控线阵辐射主瓣的方法并用实验测量结果进行了校验,二者取得了良好的一致性.研究表明,当相控线阵阵元幅度由阵的中心向两边对称单调增加时,阵的辐射主瓣角会变窄,反之变宽.

On Experiment of Amplitude Weighting of the Linear Phased Array Used in Acoustic Well Logging

In the acoustic well logging, using linear phased array acoustic transmitters can make the acoustic energy radiate to the side of receivers, which can increase the S/N ratio and the depth of investigation . The amplitude weight of a linear phased array can change the main lobe width. This technique has a promising future in the acoustic well logging. In this paper, we derived the directivity function of the amplitude-weighted linear phased array acoustic transmitter and studied the method of increasing or decreasing the main lobe width by the amplitude weight method. We used experiments to verify this method and got the good consistence. From this study, we know that the main lobe width of the linear phased array becomes narrow when the amplitude of array cells increases monotonously from the array center to its two sides. On the contrary, the main lobe width becomes wide. These results provide the experimental foundation for the design of phased array acoustic well logging tools.