Abstract: 3D prestack depth migration technique has been applied for processing of 3D prestack depth migration to some complex areas, and the results are satisfactory. The main steps can be described as follows: 1) develop time model by picking up velocity horizons in time section;2) develop interval-depth model by interval velocities layer by layer obtained by coherent inversion and stacking velocity inversion methods;3) optimize the geologic model by residual velocity analysis, and 4) achieve 3D prestack depth migration by using Kirchhoff integral method or finite differential method.

Key words: comnlex structure, 3D mieration:-prestack migration, depth migration, interval velocitv, geologic model, Kirchhoff inteeral method, finite differential method