摘要 |
In an acoustic logging system for providing information regarding selected parameters of the wall of a borehole in the earth, and of the rock formation which is adjacent the borehole, in which a single transmit/receive transducer system (T/RTS) mounted on a rotating assembly probes the wall of the borehole in a circular scanning pattern as a function of depth, the improvement which includes at least a second T/RTS mounted on the rotating assembly in known geometrical relation to the first T/RTS, and means to process two or more analog electrical scan signals for transmission over one or more electrical transmission channels in a logging cable. In particular, methods and means are described for the transmission of multiple scan signals, whereby more bottom hole parameters are transmitted, including composite electrical scan signals, in which the early part provides a gated high frequency scan signal and the latter part, the gated flow frequency scan signal, for greater penetration into the rock. Also the simultaneous transmission of multiple pairs of digital measurements of amplitude and caliper, are multiplexed over a single analog transmission system.
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