Application of Migration Velocity Using Fourier Transform Approach to Process 3-D Seismic Data

Abstract

Application of velocity by Fourier transform to process 3-D unmigrated seismic sections has been carried out in Fabi Field, Niger Delta – Nigeria. Usually, all seismic events (sections) are characterized by spikes or noise (random or coherent), multiples and shear waves so that when a seismic bed is dipping, the apparent position of reflection on a stacked section will differ considerably from its positions in the subsurface. This paper therefore brings to the fore how Migration velocity by Fourier transform can be apply in processing seismic data. The ultimate aim of this method of processing seismic data is to link seismic sections with geologic sections, positions seismic energy in space and time so that the seismic images will look like the geologic structures that generated it, collapses diffractions to points and improves spatial resolution. Based on this method, information from the field was fully processed and the results shows that dipping horizons becomes steeper, shallower and move laterally up-dip, synclines becomes broader while bow ties were completely eliminated, diffractions collapse to points and migration effects increases with depth. Finally this study has shown qualitatively how geological interpretation can be facilitated from the seismic sections thus implementing the physics of wave propagation.