Architecture and geomorphology of fluvial channel systems in the Arabian Basin

The architecture and geomorphology of fluvial channel system plays an important role in the interpretation of its sedimentary processes and characterization of the ability for subsurface storage. In the Arabian Basin, this system is considered a new petroleum play after a century of carbonate-play dominance with enormous petroleum reserves. In addition, the presence of publicly available 3D seismic refection data in the Arabian Basin is very limited, providing a condition that fluvial channel system knowledge becomes publicly less understood. Therefore, our study utilizes 3D seismic reflection data and aims to (1) interpret seismic facies and architecture, (2) map the unit thickness and lateral distribution, and (3) calculate morphometry of the Late Carboniferous to Early Permian fluvial channel systems in the Arabian Basin, and discuss its sedimentary processes, development and petroleum prospectivity. Seismic facies and seismic attribute analysis revealed three distinct fluvial channel systems including their crevasse-splay and flood plain. The channels are characterized by isolated bright on the RMS amplitudes, spectral decomposition, variance and sweetness with sinuous geomorphology and lobes (crevasse-splay) and variation of amplitude values in hummocky to sub-parallel and parallel (flood plain) reflection configuration. The morphometric analysis shows three clusters on the scaling relationship between maximum channel width and meander belt width, as well as the minor variation on the channel sinuosity index. These results indicated the dominance of the bed-load sediment transport mechanism in the fluvial depositional environment with a single-story channel body architecture. These factors provide the ability for fluvial channel systems in the studied area to act as petroleum reservoir as well as potential source rock, cap rock and stratigraphic traps. Furthermore, a single-story channel body indicated poorly connected among them, both in lateral and vertical extends that required horizontal wellbore for drainage the reservoir. Our study revealed that fluvial channel systems in the Arabian Basin has potentiality both in petroleum prospectivity as well as subsurface storage (carbon dioxide, waste, hydrogen). In addition, the workflow presented here could be applicable to characterize the fluvial channel system from 3D seismic reflection data in other basins, worldwide.