Seismic spectral decomposition for enhanced subsurface imaging of fluvial channels in the west NU field, western desert, Egypt

Abstract

Mapping fluvial channel sands in the Alam Elbueib Formation of the Shushan Basin (West NU Field, Western Desert, Egypt) presents a significant challenge due to their complex geometry and sub-seismic thickness. This study introduces an optimized workflow using spectral decomposition of conventional seismic data to predict channel trends. By integrating high (40 Hz), intermediate (30 Hz), and low (15 Hz) frequency components into an RGB color-blended model, we successfully illuminate the spatial distribution and internal architecture of reservoir-quality channel sands. The interpreted channel geometries are validated through integration with well log data, demonstrating excellent correlation with gamma ray responses and hydrocarbon shows. Wells penetrating the imaged channel fairway encountered hydrocarbon accumulations with oil shows confirmed by well logs, while a well outside the channel complex proved dry. Results reveal a meandering channel system with NNE-SSW orientation, where hydrocarbon accumulation is controlled by a hybrid structural-stratigraphic trap. This cost-effective technique serves as a powerful tool for stratigraphic analysis and direct hydrocarbon indication, providing a robust approach for de-risking exploration in fluvial-deltaic systems globally.