Seismic interpretation, structural and property modelling of Cenomanian siliciclastic/carbonates Abu Roash reservoirs in the El Diyur field (Abu Gharadig Basin, NW Desert, Egypt): Implications for reservoir architecture, distribution and evaluation

Abstract

This study presents a comprehensive integration of seismic and petrophysical assessment of the Abu Roash “G" Member in the El Diyur Oil Field, east Abu Gharadig Basin, aiming to characterise reservoir heterogeneity and evaluate hydrocarbon potential in a complex faulted setting. The overall integration of seismic, structural, and petrophysical data was employed to delineate the reservoir's structural configuration, lithological variations, and lateral distribution of reservoir properties. Seismic interpretation revealed a sheet-like geometry with the northward-dipping reflectors intersected by a major east-west trending, south-dipping normal fault (F1) and a minor subsidiary fault (F2). Fault-dependent closures created by F1 were identified as the key structural traps for hydrocarbon accumulation. Petrophysical evaluations highlighted distinct lithological variations across the Abu Roash “G-10,” “G-15,” and “G-20″ zones, with G-10 dominated by reservoir sandstones, G-15 by bioclastic limestone, and G-20 by calcareous sandstone interbedded with siltstone. Key reservoir attributes, including effective porosity, water saturation, and clay volume, exhibited lateral variations influenced by both facies and structural controls. Structural and facies modelling, incorporating fault and horizon reconstruction, underscored the impact of structural configuration on reservoir quality and hydrocarbon distribution. Depositional models suggested deltaic and tidal settings, which significantly influenced porosity and water saturation profiles. The outputs emphasise the critical role of integrated structural-petrophysical modelling in understanding reservoir heterogeneity and hydrocarbon accumulation, providing valuable insights for future exploration and development strategies in the El Diyur Oil Field and similar oil fields.