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Previous: The effective medium
Up: Well logs as tensorial quantities
Next: Assumptions
Previous Page: The effective medium
Next Page: Surface seismic
Seismic measurements at different scales have different objectives
and may result different observations.
However, the measured property still pertains
to a unique medium. Thus in theory it should be possible
to relate differently scaled measurements to one another.
In the past, there seems to have been a lack of success in this regard.
Typically, NMO velocities from surface seismics do not tie well with sonic
logs. This has been a long recognized problem.
For example, check shots are used to stretch the seismic log to
a surface seismic scale.
I assume that velocity varies not too drastically over the given frequency
interval, such that velocity dispersion will not be accounted for.
However, equivalent medium schemes suggest ways
to relate measurements carried out at different scales.
Additionally one knows exactly which quantities are
preserved in the rescaling process.
Figure 1: [ IMAGE ]
![[ IMAGE ]](_12949_dummy42.gif){kind=link}