摘要 |
Illustrative embodiments of the present invention include a transducer for acoustic well logging, comprising a cylindrical hollow body which is capable of vibrating radially and longitudinally with respect to its axis, and an hemispherical cap coupled to one end of the hollow body. A transducer of this type has a directivity pattern in the range of angles of about 15 DEG to 75 DEG to its axis. This range includes substantially all the acoustic waves whose angles of incidence at the interface between the drilling mud and the formations fall in the range of limit refraction angles typically encountered for the drilling mud commonly used and the various different kinds of formations usually investigated.
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