paul sava

Residual migrationResidual migration converts an image obtained with a given velocity model to another image corresponding to another velocity model. One way of doing residual migration is in the frequency domain, a method known as Stolt residual migration. Stolt's method can be generalized to prestack data and can be formulated function of a scalar parameter representing the ratio of of the new and original velocities. Residual migration has a direct application to migration velocity analysis. The movies show the same image which is residually migrated to different velocities. In the first movie, the depth of the events in the image are changing with depth as the velocity changes. This is natural behavior, but makes velocity analysis difficult since all events move around the image. In the second movie, the images are stretched to the original depth, such that all events move laterally, but not vertically. The diffractions corresponding to the terminations of the events focus and defocus function of velocity. Focusing analysis can be used for velocity analysis of single offset images. ReferencesSava, P.C., 2003, Prestack residual migration in the Fourier domain, Geophysics, v. 68, no. 2, pp. 634640. (PDF)
