Revealing subsurface subtle channel boundaries and fluid discrimination by employing time-frequency analysis on pre-stack seismic data, a case study: Simian Field, Offshore Nile Delta, Egypt

Abstract

It is quite difficult to determine the interior depositional architecture and fluid signature of slope channel systems in offshore deltas by using conventional seismic data as occasionally the subsurface channels might not give a clear response to the seismic images. Utilizing the spectrum decomposition approach, the Pre-stack seismic data is highly beneficial for depositional and hydrocarbon highlights. Far-angle stacks are also better for fluid identification than near-angle stacks because they have more low-frequency components and a lower signal-to-noise ratio (SNR) than near-angle stacks, which are more marked by a depositional signature.In the present study, the spectral decomposition approach, which concentrates on processing Discrete Fourier Transform (DFT) around a specified structural map, is implemented to transpose the amplitude or phase data into the frequency domain. Red-Green-Blue (RGB) blending map was extracted from the near and far-stack seismic data, through which the channel depositional geometries become clear. However, utilizing RGB on the far stack made the fluid signature fairly obvious.