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AAPG GEO 2010 Middle East
Geoscience Conference & Exhibition
Innovative Geoscience Solutions – Meeting Hydrocarbon Demand in Changing Times
March 7-10, 2010 – Manama, Bahrain

Gaussian Beam De-Previous HitMigrationNext Hit and Re-Previous HitMigrationNext Hit

Jianming Sheng1; Chengbin Peng1

(1) Nexus Geosciences Inc., Sugar Land, TX.

In this abstract we will present a theoretical framework for demigration of seismic image Previous HitdataNext Hit under the frame work of Gaussian Beam theory. The underlying methodology has no dip limitation and handles multi-valued arrivals well. The practical use of this technology is to perform prestack demigration of existing image volumes (CIG gathers) followed by prestack depth remigration using a replacement velocity and/or anisotropy model. The result is a fast, accurate, and cost effective way to improved seismic imaging as compared to proprietary reprocessing from field tapes.

Ross Hill published seminal works in Previous HitcommonNext Hit Previous HitoffsetNext Hit Gaussian Beam prestack depth Previous HitmigrationNext Hit (Hill, 1991 and 2001). Chevron has been largely the only beneficiary of the Gaussian beam technology. To the best of our knowledge there have been no published work on Gaussian beam prestack demigration.

For example, in prestack demigration, one can start with an individual Previous HitcommonNext Hit Previous HitoffsetNext Hit image volume (Kirchhoff Previous HitmigrationNext Hit volume, Gaussian beam Previous HitmigrationNext Hit volume, or fast beam Previous HitmigrationNext Hit volume). The single fold image is demigrated to reconstruct the corresponding input unmigrated seismic Previous HitdataNext Hit. In Gaussian Beam prestack demigration, we actually reconstruct the individual beams used as input to the original Gaussian Beam Previous HitmigrationNext Hit. The individual beams are then synthesized to form an unmigrated seismic volume.

There are many uses of Gausian Beam prestack demigration technology. For example, it can be used as a fast forward modeling tool to generate synthetic Previous HitdataNext Hit for Previous HitmigrationNext Hit and inversion. Another use of this technology is to perform prestack demigration of existing image Previous HitdataNext Hit, followed by prestack depth (re)Previous HitmigrationNext Hit with a replacement velocity and/or anisotropy model. This is a faster, more accurate and cost effective way of seismic imaging over proprietary reprocessing from field tapes. Both synthetic and field Previous HitdataTop examples of this will be shown.