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Application of the intercept time method to full wave form acoustic data
- Source: First Break, Volume 13, Issue 1, Jan 1995,
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- 01 Jan 1995
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Abstract
Formation slowness is commonly estimated using first motion detection of the compressional headwave recorded with an acoustic tooI. This slowness estimation, in its simplest form, involves the difference in arrival time between two or more receivers. However, additional information is embodied in the traveltimes themselves. The measured traveltime at each receiver is actually a function of the path of the signal between the source and the receiver. In the presence of near-borehole changes in formation slowness, such as in altered or damaged zones (implying a reduction in the formation velocity in the vicinity of the borehole), refracted borehole arrivals may pass some inches to some feet from the borehole wall.
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