Reservoir Quality Assessment Using Petrophysical Analysis in Uzondu Field, Niger Delta Basin

Abstract

Reservoir quality assessment using petrophysical analysis in Uzondu Field, Niger Delta Basin was carried out using Well log data. The target for this study was the Zone A-E (W, X, Y, Z series) reservoir sands of wells Uzondu_A-E with depth range of 8155ft to 12320ft across the five wells.  Well log data were analyzed using Interactive Petrophysics (IP2018) software to evaluate key petrophysical parameters such as shale volume (Vsh), effective porosity (Φe), water saturation (Sw), permeability (via Timur’s equation), and net-to-gross ratio for the Zones A-E (W, X, Y, Z series) reservoir units. The results indicate that Uzondu_A contains high-quality, hydrocarbon-bearing clean sandstones with high porosity (up to 0.40), very high permeability (up to 2,860 mD), and low water saturation. Uzondu_B shows good to very good reservoir properties with moderate heterogeneity, while Uzondu_C exhibits moderate to poor quality due to increasing shale content. Uzondu_D is interpreted as non-reservoir, and Uzondu_E represents a marginal, shale-dominated sector with high water saturation and low permeability. Lateral correlation demonstrates a core productive zone centered around Uzondu_A and Uzondu_B, with reservoir quality diminishing toward the field margins. The study concludes that reservoir quality in the Uzondu Field is primarily controlled by porosity and shale content, with fluid saturation exerting a secondary influence.
DOI: https://doi.org/10.5281/zenodo.18904286