Interpretation of seismic data and 3D structural and property modeling of siliciclastic Pliocene reservoirs in the Denise Field (eastern Nile delta Offshore): Insights for reservoir architecture and assessment

Abstract

This study integrates seismic interpretation and 3D structural and petrophysical modeling to characterize the Pliocene siliciclastic reservoirs of the Denise Field in the offshore Eastern Nile Delta, focusing on reservoir geometry, spatial distribution, and quality assessment. Seismic interpretation reveals a complex structural framework dominated by E-W trending growth faults (F1–F6) linked to Jurassic crustal extension, alongside NNE-SSW trending Rosetta faults associated with transpressional movement. A prominent rollover anticline and gas chimneys further influence hydrocarbon migration and accumulation. Petrophysical evaluation of the Kafr El Sheikh Formation identifies three key reservoir units: Pre U. Denise S.S., U. Denise S.S., and L. Denise S.S. The U. Denise S.S. unit, the primary reservoir, exhibits high porosity (15–30 %) and variable water saturation (20–42 %), with net pay thicknesses ranging from 52 to 130 m. The L. Denise S.S. unit shows consistent high porosity (17–32 %) but higher water saturation (30–40 %), while the Pre U. Denise S.S. unit is limited in distribution, with moderate porosity (15–35 %). 3D structural modeling highlights fault-controlled horst and graben structures, with sealing faults (F2, F3, F5) potentially compartmentalizing the reservoir. Facies modeling indicates NW-SE trending sand bodies, with the U. Denise S.S. unit exhibiting the highest sand content. Petrophysical modeling reveals strong porosity-permeability correlations, with gas-bearing zones concentrated in high-porosity regions. The study identifies the northwestern channel trend as the most favorable reservoir zone, while increased shale content and water saturation degrade reservoir quality in the central basin trend. These findings provide critical insights for reservoir development and future exploration in the Denise Field. Moreover, these results underscore the critical control of seismic interpretation and reservoir modelling on reservoir distribution and quality. These methodologies and findings provide a transferable framework with broad international significance, offering essential insights for future exploration targeting in analogous settings worldwide.