Data regularization can be applied before Kirchhoff prestack depth migration as a preprocessing step, in the same way as it is performed prior to wave equation prestack migration. Its importance and the related trade-off between quality of results and speed-up are discussed. Whilst 3D wave equation based prestack depth migration is shown to give better results than Kirchhoff on synthetic data, the results on field data are of more comparable quality in our experience. Taking into account the cost factor, we propose to also consider multi-valued "full" Kirchhoff migration as a good compromise for prestack depth migration.
Kirchhoff based 3D prestack depth migration has become the standard operational tool for seismic depth imaging in recent years. Kirchhoff theory, however, is related to ray theory and the eikonal equation with their well known limitations and this makes wave-based methods the natural choice as a base for improved migration methods.