Migration velocity analysis by double path-integral migration

摘要

The idea of path-integral imaging is to sum over the migratedimages obtained for a set of migration velocity models.Velocities where common-image gathers align horizontallyare stationary, thus favoring these images in the overallstack. The overall image formswith no knowledge of the truevelocity model. However, the velocity information associatedwith the final image can be determined in the process. Byexecuting the path-integral imaging twice and weighting oneof the stacks with the velocity value, the stationary velocitiesthat produce the final image can then be extracted by a divisionof the two images. The velocity extraction, interpolation,and smoothing can be done fully automatically, withoutthe need for human interpretation or other intervention. Anumerical example demonstrated that quantitative informationabout the migration velocity model can be determined bydouble path-integral migration. The so-obtained velocitymodel can then be used as a starting model for subsequent velocityanalysis tools like migration velocity analysis or tomographicmethods.