TIME‐TO‐DEPTH CONVERSION IN THE PRESENCE OF STRUCTURE

Abstract

Time‐to‐depth conversion has long since been one of the objectives of seismic interpretation. Unfortunately, there is not a straightforward procedure that derives a depth section from a time section. This is due to the fact that reflection times depend upon the positions and shapes of the interfaces as well as upon the interval velocities, which are both unknown. A program will be described to handle this problem under fairly general conditions. An estimated depth section is updated in an iterative way, depending on the differences between reflection‐time data of the input and that derived with ray tracing from the estimated depth section. The program starts with the first layer and, after completion, continues with the second, etc. The main assumptions are that there is no crossdip and that the interval velocity within each layer is a linear function of depth and lateral position.