** Next:** ACKNOWLEDGMENTS
** Up:** Cunha: Well-to-well correlation
** Previous:** Instantaneous variation

There are several possible ways in which well-logs can be correlated.
The choice of the matching attribute must be controlled by the geologic
feature that one is trying to resolve. A smoothed version of the
sonic log is most appropriate for lithologic matching, and can therefore
be used as a constraint to a tomographic inversion. In this case, remains
the question of whether to match amplitudes
or shapes, a choice that can be particularly critical when a strong lateral
velocity variation is present. Moreover, if the goal is to find
the correlation between chronostratigraphic units that are resolved
in a surface seismic section, the usual synthetic seismogram may not
be the optimal choice.
Extensive lateral continuity in a seismic section is related to the specific
patterns in the impedance transitions, rather than to the transition values.
As a result, the output of a filter that measures the local variability of
the sonic log provides a better chronostratigraphic correlation between wells
covering an extensive area than conventional synthetic seismograms.

** Next:** ACKNOWLEDGMENTS
** Up:** Cunha: Well-to-well correlation
** Previous:** Instantaneous variation
Stanford Exploration Project

12/18/1997