Geoscience Reference
In-Depth Information
Is there adequate data coverage to map the features?
Are the features consistent from line to line?
Do the features show conformance with depth structure?
Are the effects consistent with analogues?
Fluid effects are sometimes more visible on seismic than Gassmann modelling
suggests we have a right to expect; for this reason, we should always look for structure-
conforming amplitude change in the real seismic data, even where modelling says that
the effects may be too small to see. It is sometimes possible to see the effect of hy-
drocarbons indirectly, because they tend to preserve porosity during diagenesis. The
biggest problem in understanding amplitude anomalies is the need to bear in mind a
rich enough set of possible explanations. In particular, it is hard to anticipate effects due
to lateral lithological change different from any recorded in existing wells in the area;
generation of a range of geological models, based on analogues, is the key to exploring
the possibilities.
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