AbstractThe increasing use of velocity analysis programs in seismic processing in addition to direct application to normal move out corrections often makes it possible to study the variation of the average velocity versus time and distance. Usually, it is even feasible to compute interval velocities with a good accuracy.We intend to use these velocities to convert the usual time domain displays to the depth domain.An exact conversion requires the knowledge of all interval velocities and all the velocity interfaces.However, when the dips are small, the conversion can be done without considering the dip of all these interfaces, and in some cases migration can even be completely neglected.Three different programs will be described and their use discussed in view of the type of problems to which they are applied.Practical examples of the various methods will be presented.