This paper presents results of a study conducted to determine and evaluate the petrophysical properties of "SEYI" oil field, Niger delta with a view to understand their effects on the reservoirs hydrocarbon prospect and oil productivity of the field. The evaluated properties include porosity, permeability, fluid saturation, net / gross thickness and mobility which are all inferred from geophysical wire-line logs. A suite of wire-line logs comprising of gamma ray, resistivity, spontaneous potential and density logs for four wells from 'SEYI' oil field were analysed for reservoir characterisation of the field. The analyses carried out involves delineation of lithologies, identification of reservoirs and fluid types, wells correlation and determination of petrophysical parameters of identified reservoirs. Seven reservoirs namely: A, B, C, D, E, F and G were delineated with their tops and bases at depth from 2396m to 3429m. Their analysis indicate the presence of hydrocarbon in all the reservoirs. Computed petrophysical parameters across the reservoirs gave porosity as ranging from 0.22 to 0.31; permeability 881.58md to 14425.01md and average hydrocarbon saturation of 41.44%, 20.29%, 30.82%, 37.92%, 51.20%, 91.97% and 85.11% for reservoir A, B, C, D, E, F and G respectively. These results together with the determined movable hydrocarbon index (MHI) values (0.05 to 0.75) of the reservoir units suggest high hydrocarbon potential and a reservoir system whose performance is considered satisfactory for hydrocarbon production.