Method and system for migration of seismic data

#The present invention relates to seismic data processing, and more particularly to a more rapid method of migrating seismic data for steeply-dipping reflectors and large lateral variations in velocity.

#Typically, seismic data is arranged in arrays representing an acoustic signal received by sensors. Often the seismic data represents signal values as a function of geometric location and frequency content of the signal. Geological sensors, like geophones and hydrophones, measure the wavefields at a multitude of positions. The measured seismic data characterized by wavefields are processed to identify useful geological formations. One such processing step is called seismic data migration.

#Seismic data migration requires solving the wave equation in the earth volume. Measured wavefield data points are used in conjunction with the wave equation to identify useful geological formations. It is well known in the art that the seismic data requires migration in order to restore the apparent positions of reflections to their correct locations (Claerbout1, 1999; Stolt and Benson2, 1986). Numerous techniques of seismic data migration are known in the art (Bording and Lines3, 1997; Claerbout4, 1999; Stolt and Benson5, 1986). Different techniques provide differing degrees of accuracy. In general, more accurate methods require greater computational resources. In order to use available computer resources in a cost-effective manner, computation-intensive algorithms must be designed as efficiently as possible.

#FIG. 1 is a diagram of an example method embodiment of the present invention.

#FIG. 2 is a diagram of an example system embodiment of the present invention.

#A method of migrating seismic data is provided. The seismic data has associated therewith a wavefield at a first level. The method comprises extrapolating the wavefield from the first level to a second level; correcting the extrapolated wavefield; computing intermediate sample points for an output image between the first and the second levels; computing a contribution to the wavefield at each intermediate sample point; and summing the contributions to the wavefield at each intermediate sample point.

#A system for migrating seismic data is provided. The system comprises means for extrapolating a wavefield; means for correcting the extrapolated wavefield; means for computing intermediate sample points for an output image; means for computing a contribution to the wavefield at each intermediate sample point; and means for summing the contributions to the wavefield at each intermediate sample point.

#Depth Migration