Reservoir description and modelling using integrated seismic and petrophysical data in AKDB-field, offshore Niger delta, Nigeria

Abstract Reservoir heterogeneity in the Niger Delta presents a major challenge to optimize hydrocarbon recovery and accurately predicting production potential. To address this problem, this study integrates three-dimensional (3D) seismic data with well log analyses to characterise reservoir architecture and evaluate hydrocarbon distribution within the AKDB Field. Petrophysical analysis of four wells identified six reservoirs of which four (B, C, D and F) exhibited significant hydrocarbon potential. Deterministic modelling revealed key reservoir properties which includes porosity values ranging from 15.86% to 35.86%, permeability between 891 and 11 181 millidarcies, and hydrocarbon saturation metrics with reservoir F emerging as the most promising interval (61.21% hydrocarbon saturation and 26.73% effective porosity). Seismic structural interpretation delineated 36 faults and 8 stratigraphic horizons. Depth conversion was achieved using third-order polynomial velocity model. Subsequent static 3D reservoir modelling, employing Sequential Gaussian Simulation (SGS) and Indicator Simulation (SI) techniques, was used to spatially distribute facies (sandstone, sandy shale, and shale) and related petrophysical parameters. Among the analysed unit’s reservoir F shown the highest net-to-gross ratio (75.40%) and permeability (3624 mD), whereas reservoir C contained the largest stock-tank oil initially in place estimated at 4170 MSTB. The AKDB Field is structurally complex with rollover anticlines and growth faults influencing hydrocarbon trapping. Globally, these results emphasise subsurface heterogeneity and highlight reservoir F and C as primary targets for field for development. The study enhances understanding of reservoir architecture, performance and supports improved field development planning and contributing to long-term energy security strategies in Nigeria.