Acoustic data compression technique

摘要

Acoustic data acquired in a MWD/LWD system can be compressed for transmission to the surface. The compression technique can include semblance processing acoustic signals received at a plurality of receivers spaced apart from a transmitter to generate a semblance projection at each of a plurality of depths. Peaks of the semblance projection can then be telemetered to the surface, with each peak including a slowness (velocity) value and a coherence (semblance) value. The telemetered values may be processed at the surface to generate logs as a function of depth.

主权项

1. A method of acquiring and processing acoustic data in a logging while drilling (LWD) system, the method comprising:
firing an acoustic transmitter; receiving acoustic signals at a plurality of receivers spaced apart from the transmitter, said acoustic signals having interacted with a formation; semblance processing by generating data indicative of slowness as a function of arrival time from the received acoustic signals and generating a semblance projection from the generated data for each of a plurality of depths; and telemetering one or more peak values of said semblance projection for each of the plurality of depths to the surface, wherein the one or more telemetered peak values include at least a slowness measurement and a coherence value.