Dip-dependent spreading correction through prestack migration/inversion
- Statoil, Trondheim (Norway)
Fazzari (1992) showed that the conventional geometrical spreading correction used in seismic processing is incorrect for dipping beds at large travel times. This can be remediated by using a dip-dependent geometrical spreading correction, as was demonstrated by Fazzari. The authors show that it is also possible to provide exactly the same spherical spreading correction via prestack migration by modifying existing scheme slightly. This modification is derived via a least-squares inverse scheme relating seismic data to reflection coefficients. The scheme also works for poststack data, but would require the use of a true zero-offset model for migration instead of the standard exploding reflector model. For illustration two simple data examples are provided. In the first examples 3-D prestack migration schemes are used to image two point-diffractors. The conventional schemes grossly underestimates the strength of the diffractors. A modified scheme is shown to provide a much more correct amplitude. The data for the second example consists of a single split-spread record shot over a steeply dipping reflector. The results of conventional and modified 2-D prestack schemes are compared, and the modified scheme is shown to provide better estimates of the reflection coefficient.
- OSTI ID:
- 80272
- Report Number(s):
- CONF-941015--
- Country of Publication:
- United States
- Language:
- English
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