A method for modeling reflection data from media with lateral velocity changes

摘要: A new method of modeling zero offset reflection data accommodates both vertical and lateral velocity variations allows continuous changes in reflectivity throughout the section. Each point subsurface is considered a scatterer, energy at each distributed over diffraction curve that would be observed if it were only scatterer subsurface. When varies with depth, curves are relatively simple to determine. Computing when there variations, however, requires extensive ray tracing. Our avoids trace by approximating exact perturbed computed for model which depth. The slowness (reciprocal velocity) function written as sum two functions: first large depends on depth other small position along line. Ray paths traced used calculate curves. For these same travel time perturbations due laterally varying part slowness. added obtain an approximation curve.