The Application of Seismic Spectral Coherence to the Identification and Delineation of Stratigraphic Features in Niger Delta

Abstract

Seismic spectral coherency images discontinuities by measuring lateral changes in the seismic response caused by variation in structure, stratigraphy,lithology,porosity and the presence of hydrocarbon, in terms of ratio of trace energies, in frequency domain. It operates on the seismic data itself. The aim of the study was to develop a robust technique for mapping subtle stratigraphic units. The methodology combined conventional coherence technique and non-conventional technique of the discrete Fourier transform. The geologic features were analyzed over a narrow time gate centered on the top of a thin sand interval..The response attribute maps,e.g magnitude,phase,and frequency revealed hidden stratigraphic features.

Keywords: Discrete Fourier transform, Coherence, Semblance, Spectral decomposition