相控线阵声波测井辐射器指向性影响因素研究

On Influencing Factors of the Directivity of Phased Array Transmitter in Acoustic Log

从基础物理实验着手 ,分析了相控线阵声波测井辐射器相邻阵元间激励延迟时间、声源频率、阵元间距、阵元个数、幅度加权等参数对相控线阵声波辐射器的指向性影响。大量实验研究表明 ,随着阵元间激励延迟时间的增加 ,相控线阵辐射声束主瓣角不断增大 ;随着声源频率降低、阵元间距减小、阵元个数减少以及适当的幅度加权可以使相控线阵辐射声束主瓣角不断变宽。实验测量数据与理论计算结果吻合较好。这为相控线阵声波辐射器在实际测井中的应用提供了设计依据。

Based on the experiments in the laboratory, we studied the influence on the directivity of the phased array transmitter in acoustic logging, which includes time delay exerted on neighboring elements, acoustic wave frequency, inter-element spacing of a phased array, the number of the elements, etc. Experimental results show that, by increasing the time delay exerted on neighboring elements, steered radiation angle of the phased array becomes larger and larger; by lowering the acoustic wave frequency, reducing inter-element spacing, decreasing the number of the elements or using weighted phased array, main radiation lobe of phased array can be widened gradually. The results of experiment are in good agreement with that of the calculations, which offers a design guidance for the phased array transmitter to be used in the acoustic log in the field.