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Well Log

Here we consider well logs as being at the lowest spectrum of scales. In general there can be scale overlap with Cross Well measurements, but it is very unlikely that there is overlap with any other of the listed experiments.

 
velp
velp
Figure 2
A well log, showing the P wave sonic velocity with depth.
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pickrms
pickrms
Figure 3
The stacking velocity (dashed line) picked from a conventional velocity analysis is compared to the rms velocity (solid line) calculated from the original P wave sonic in Fig 2.
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Obviously the most challenging task is then to relate well log with surface seismic measurements. Fig 2 and 3 show stacking velocity and sonic log obtained at the same surface location. We can clearly see how experimental scale differences can lead to quite different results in resolution and values, although they both measure the same medium. This well-known problem exists when comparing borehole sonic logs and surface seismic velocity estimations.


previous up next print clean
Next: ASSUMPTIONS Up: TYPICAL SEISMIC EXPERIMENT SCALES Previous: Cross Well
Stanford Exploration Project
11/17/1997