Method of processing seismic data by providing surface offset common image gathers

摘要

The method processes input including, for each of a plurality of shots at respective source locations, seismic traces recorded at a plurality of receiver locations. Offset-modulated data are also computed by multiplying the seismic data in each seismic trace by a horizontal offset between the source and receiver locations for said seismic trace. A depth migration process is applied to the seismic data to obtain a first set of migrated data, and to the offset-modulated data to obtain a second set of migrated data. For each shot, offset values are estimated and associated with respective subsurface positions, by a division process applied to the first and second sets of migrated data.

主权项

1. A method of seismic inspection of a subsoil region, comprising:
firing a plurality of shots at respective source locations to propagate seismic waves in the subsoil region; recording seismic traces at a plurality of receiver locations in response to the plurality of shots to generate seismic data including, for each of the plurality of shots at the respective source locations, seismic traces recorded at the plurality of receiver locations; applying a depth migration process to the seismic data to obtain a first set of migrated data including, for each shot, first migrated values respectively associated with a plurality of subsurface positions; computing offset-modulated data by multiplying the seismic data in each seismic trace by a horizontal offset between the source and receiver locations for said seismic trace; applying the depth migration process to the offset-modulated data to obtain a second set of migrated data including, for each shot, second migrated values respectively associated with the plurality of subsurface positions; for each shot, estimating offset values respectively associated with at least some of the subsurface positions, by a division process applied to the first and second sets of migrated data; and estimating a common image gather at a horizontal position, comprising respective migrated values for parameter pairs each including a depth parameter and an offset parameter,
wherein the migrated value for a parameter pair in the common image gather at said horizontal position is a first migrated value of the first set of migrated data associated with a subsurface position determined by said horizontal position and the depth parameter of said parameter pair for a shot such that the estimated offset value associated with said subsurface position is the offset parameter of said parameter pair.