Título: Migration velocity analysis based on common-shot-depth migration applied to the seismic data of the caribbean oceanic plateau

Autor: Leroy, S.; Maufret, A.; Bitri, A.

Fuente: Geophys. J. Int., 125(1): 199-213, April 1996

Descriptores: Caribbean Sea; Atlantic Ocean; Calculating; Data Processing; Interval Velocity; Mathematics; Migration (Seismic); Venezuelan Basin; Seas and Oceans; Seismic Data Processing

Año: 1996

País de publicación: France

Tipo de documento: Articulo

Resumen

In areas where the geology is characterized by strong vertical and lateral velocity gradients, prestack depth migration will produce the optimum subsurface image. An accurate velocity model is required for an accurate prestack depth migration. A velocity analysis was developed, based on recursive prestack depth migration that gives better results than the traditional CMP velocity analysis when applied to data over the Caribbean oceanic plateau. First, the shot records are migrated with a series of constant velocities for each identified geological layer. The velocity that best flattens the event in common-receiver gathers is picked. A large number of velocity analyses are run along the seismic line in order to define the reflector geometry. For each layer, the depth and interval velocity are obtained in order to make a model down to that depth. This model is then used as the input for the next layer velocity analysis. Finally, when all the layers have been picked, the entire line is depth migrated with the derived model.