ZHANG Bixing1,2 ZHANG Chengguang2 Deng Fangqing1 

(1 State key Laboratory of Acoustics, Institute of Acoustics , Chinese Academy of Sciences Beijing 100190)

(2 School of Geophysics Oil Resources, Yangtze University Jingzhou 434023) 

Received Jun.27, 2008

Revised Jul.14, 2008  

Abstract The non-integral dimensions ultrasonic phased arrays and their scanning and testing methods in a borehole are studied. First, the focusing acoustic fields excited by the 1.25D,1.5D, and 1.75D phased arrays are analyzed, and then the imaging resolution in the elevation direction and the influence of the dynamic elements are investigated. Second, the focusing and deflexion characteristics of the acoustic fields excited by the annular and segmented annular phased arrays are studied, and they are compared with those excited by the 2D surface array. The application method of the 1.25D, 1.5D, and 1.75D,annular and segmented annular phased arrsys in acoustic logging are analyzed and discussed. It provides a theoretical foundation for the application of the ultrasonic phased arrays in acoustic logging.

PACS numbers: 43.20, 43.25, 43.38