Borehole Acoustics –New Approaches to Old Problems - Wave Propagation in Drilling, Well Logging and Reservoir Applications - page 367

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Borehole Acoustics -
New Approaches to Old Problems
In this final chapter, we discuss new approaches to wave propagation, this
time, addressing borehole acoustics (or geophysics) applications. We focus on
two important problems, the first related to permeability prediction from
Stoneley waves, and the second, the modeling of borehole eccentricity critical to
horizontal wells. We first give an interesting discussion illustrating how
“kinematic wave theory” can provide additional physical insight and signal
processing versatility relative to conventional analysis methods. Wikipedia
provides a simple definition: “Stoneley waves are most commonly generated
during borehole sonic logging and vertical seismic profiling. They propagate
along the walls of a fluid-filled borehole. They make up a large part of the low-
frequency component of the signal from the seismic source and their attenuation
is sensitive to fractures and formation permeability. Therefore, analysis of
Stoneley waves can make it possible to estimate these rock properties.”
Wikipedia gives references for standard sonic log processing to derive wave
velocity and also the schematic reproduced in Figure 10.1.
Figure 10.1. Stoneley waves in (concentric) boreholes.
(Courtesy, Wikipedia, the Free Encyclopedia, Creative Commons License.)
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