Assessment of Late Miocene Reservoirs: Geophysical and Petrophysical Perspectives on Unconventional Gas in the Nidoco Field, Nile Delta, Egypt

ABSTRACT This study evaluates the hydrocarbon potential of the Late Miocene section in Nidoco Field (Central Nile Delta) through integrated petrophysical and pressure data analysis. Key reservoir units—Level‐2, Level‐3, Level‐3A, Level‐3 Lower, Unit‐A and Unit‐B—exhibit superior reservoir quality, characterised by high effective porosity (Øeff) and gas saturation (Shr). Lithological analysis reveals sandstone and shale as the dominant facies, with laminated‐to‐dispersed montmorillonite‐rich shales influencing reservoir heterogeneity. Iso‐parametric maps demonstrate lateral variations in shale content ( V sh ), porosity, and hydrocarbon distribution, highlighting compartmentalised flow units. Reservoir pressure data identify five hydraulically isolated compartments, confirming dynamic gas reservoir behaviour and validating the geological model. The integration of well‐log interpretations with pressure measurements reveals distinct pressure regimes correlating with lithological boundaries, improved porosity‐permeability relationships through NMR‐enhanced analysis, and optimal reservoir zones in Level‐3 and Unit‐B with Øeff > 18% and Shr > 65%. Results indicate substantial untapped potential, particularly in the central and eastern field sectors where reservoir quality peaks. The study's geological model successfully guided recent gas discoveries, demonstrating the effectiveness of combining petrophysical and dynamic data. The study recommends prioritising development drilling in Level‐3A and Unit‐A (highest gas saturation), implementing targeted stimulation in compartment boundaries to enhance connectivity, in addition to expanding exploration north‐westward where pressure data suggest reservoir continuity. This workflow provides a template for evaluating similar deltaic reservoirs, emphasising the critical role of integrated static‐dynamic characterisation in unlocking complex hydrocarbon systems.