Reservoir Characterization and Petrophysical Analysis of “Brown Field” in the Southern Niger Delta, Nigeria

Abstract

Accurate reservoir characterisation is essential for understanding the distribution, quality, and structural controls of hydrocarbon-bearing formations. In the Niger Delta, integration of petrophysical well-log analysis with 3-D seismic interpretation provides a basis for evaluating reservoir properties, continuity, and trapping structures. This study therefore applies an integrated petrophysical and seismic approach to characterise the reservoirs of Brown Field in the southern Niger Delta, Nigeria. An integrated reservoir characterisation and petrophysical evaluation of Brown Field, southern Niger Delta, was carried out using 3-D seismic data, check-shot data, and a suite of well logs from seven wells. The study combined petrophysical analysis, structural interpretation, reservoir delineation, and seismic-to-well tying to assess reservoir properties and structural controls on hydrocarbon occurrence. Two hydrocarbon-bearing reservoirs, P0.5 and P1, were identified and correlated across the field. The reservoirs are composed predominantly of sandstone with shale intercalations, and their thicknesses vary laterally and with depth. Petrophysical evaluation indicates water-saturation values ranging from 0.084 to 0.30, average porosity values of approximately 0.21–0.29, and gross sand thicknesses of 147–331 ft. The mapped horizons and fault framework reveal fault-associated anticlinal structures that provide structural closure and compartmentalisation. Variations in reservoir depth between wells are consistent with fault displacement, while the increasing proportion of shale with depth reflects vertical lithological variation within the succession. The integrated interpretation indicates that both reservoirs contain hydrocarbons, although their petrophysical quality differs. On the basis of the reported average reservoir parameters, P1 was classified as more prolific than P0.5. Overall, the combined well-log and seismic interpretation provides a field-scale basis for understanding reservoir distribution, quality, and structural configuration in Brown Field.