--> --> Abstract: Migration of Velocity Spectra: An Example from the Timor Sea, by J. C. Beasley and R. Klotz; #91015 (1992).
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ABSTRACT: Migration of Previous HitVelocityNext Hit Spectra: An Example from the Timor Sea

BEASLEY, J. CRAIG, and ROLF KLOTZ, Western Geophysical Company, Singapore

Successful seismic imaging of complex geology such as that found in the Timor Sea requires accurate migration of the seismic data to collapse diffractions, image faults, and position reflectors in the correct spatial location. Although today's migration algorithms in theory generally are accurate, in practice migration accuracy for steep dips critically depends on the migration Previous HitvelocityNext Hit.

An approach used routinely to estimate the migration Previous HitvelocityNext Hit is to minimize the effects of dip and azimuth by applying dip movement (DMO) to the data. However, Previous HitvelocityNext Hit derived from DMO-corrected data is located at an unmigrated position and should be repositioned prior to use as a migration Previous HitvelocityNext Hit. The effect of this phenomenon will be demonstrated through an example from the Timor Sea in which, prior to migration, reflections and diffractions from a complex system of faulted carbonates conflict with low-relief primary reflections resulting in poorly resolved Previous HitvelocityNext Hit analyses.

This problem can be overcome by employing conventional migration to migrate the DMO Previous HitvelocityNext Hit to the proper spatial location prior to migrating the seismic data. Previous HitVelocityNext Hit spectra are generated first from DMO-corrected data on a regular spatial grid and then common-Previous HitvelocityNext Hit slices are extracted and migrated. Finally, the migrated Previous HitvelocityNext Hit is reassembled at common spatial locations into Previous HitvelocityNext Hit spectra, which provide a better estimate of the true subsurface Previous HitvelocityNext Hit.

By applying conventional migration principles to migrate Previous HitvelocityNext Hit derived from DMO-corrected data, Previous HitvelocityNext Hit is placed at the correct spatial location as required for migration. The method provides an automated, efficient, and accurate procedure for determining migration Previous HitvelocityTop.

 

AAPG Search and Discovery Article #91015©1992 AAPG International Conference, Sydney, N.S.W., Australia, August 2-5, 1992 (2009)