Method and system using wave-equation for obtaining traveltime and amplitude used in Kirchhoff migration
AssigneeCgg Services SAS
InventorsHui Huang, Diancheng Wang, Ping Wang
Life of this patent
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Abstract
Limitations in accuracy and computing power requirements impeding conventional Kirchhoff migration and reverse time migration are overcome by using the wave-equation Kirchhoff, WEK, technique with Kirchhoff migration. WEK technique includes forward-propagating a low-frequency wavefield from a shot location among pre-defined source locations, calculating an arrival traveltime of a maximum amplitude of the low-frequency wavefield, and applying Kirchhoff migration using the arrival traveltime and the maximum amplitude.
Claims20
A seismic exploration method comprising:
- obtaining seismic data acquired in an area over a subsurface formation;
- migrating the seismic data based on a model of the subsurface formation and using a wave-equation Kirchhoff, WEK, technique, for pre-defined surface locations, the WEK technique including:
- forward-propagating a low-frequency wavefield from a shot location among the pre-defined locations,
- deriving an arrival traveltime of a maximum amplitude of the low-frequency wavefield, and
- applying Kirchhoff migration using the arrival traveltime and the maximum amplitude;
- and
- outputting an image of the subsurface formation based on the migrated seismic data.
A seismic data processing apparatus comprising:
- an interface configured to obtain seismic data acquired over a subsurface formation;
- and
- a data processing unit connected to the interface and configured:
- to migrate the seismic data based on a model of the subsurface formation and using a wave-equation Kirchhoff, WEK, technique for predefined source locations, the WEK technique including:
- forward-propagating a low-frequency wavefield from a shot location among the pre-defined source locations,
- deriving an arrival traveltime of a maximum amplitude of the low-frequency wavefield, and
- applying Kirchhoff migration using the arrival traveltime and the maximum amplitude;
- and
- to output an image of the subsurface formation based on the migrated seismic data.
A non-transitory computer readable recording medium storing executable codes that, when executed by a computer, make the computer perform a seismic exploration method comprising:
- obtaining seismic data acquired over a subsurface formation;
- migrating the seismic data based on a model of the subsurface formation and using a wave-equation Kirchhoff, WEK, technique for pre-defined source locations, the WEK technique including:
- forward-propagating a low-frequency wavefield from a shot location among the pre-defined source locations,
- deriving an arrival traveltime of a maximum amplitude of the low-frequency wavefield, and
- applying Kirchhoff migration using the arrival traveltime and the maximum amplitude;
- and
- outputting an image of the subsurface formation based on the migrated seismic data.
Dependencies are inferred from the claim text.