A Deterministic Evaluation of eismic Fidelity using Velocity Modeling ...

comparisons, those at the same depth, and comparisons of differences of 200 feet. In the
shallower section, around 4500 ft and 4305 feet there was not a noticeable difference
between the two PSDM volumes. I used the well-based PSDM for the final interpretation
because it imaged faults and salt more clearly at 6000 ft and 5805 feet.
5.5 Attributes for Interpretation
Coherence has been recognized and used as an interpretation tool. In this study
coherence, especially with edge preserving smoothing provided a robust interpretation
tool. Integrated with the seismic data coherence allowed interpretation of several
structural and stratigraphic features that otherwise would have been missed. Imaged
from the coherence cube were several faults and channels not easily detected in the
seismic data alone (Figure 75). Figure 75 also illustrates how the well-based model
improved the fidelity over the prestack time migrated velocity model PSDM and the
PSTM, especially deeper in the section. Another significant improvement was the ability
to accurately image the salt flanks (Figure 76). Using coherence as an interpretation tool,
contrasts between the faults and channels allowed me to interpret them (Figure 77).
Interpreting geologic features using coherence that were not imaged with seismic alone
demonstrated the robustness of coherence with edge preserving smoothing.
I also generated curvature and gradient attributes to see if they too could be used for
interpretation. To determine the degree of folding in areas of folded strata is where the
curvature attribute is most useful. I calculated the curvature attribute for the Vinton
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