Migration techniques in seismic reflection methodology : comparative review

Abstract

The migration of seismic reflection data can be categorised in three methods: Kirchhoff migration, Finite-difference migration, and Frequency-wavenumber migration methods. Kirchhoff migration is the most popular and flexible migration method and is generally the most effective in collapsing diffraction events. Finite difference migration is very useful in handling time migration, or depth migration, with complex velocity distributions. Finite-difference solutions of the wave-equation can be used to efficiently implement downward continuation and can handle laterally varying velocity fields. Frequency-Wavenumber if-k) migration is also an important method that is deemed to be the quickest when constant velocity is assumed and it is also accurate to 90°. F-k migration has two different migration methods: Stolt (1978) and Gazdag (1978) methods. These two major forms of migration are based on Fourier transforms. In this dissertation a comparative review of the three migration methods was applied on real seismic reflection data from offshore Malta. The comparative study showed that the Finite-difference migration approach gave the best results on this particular data set.