Petrophysical characterization of Reservoir Sands of Two Wells in the Offshore Depobelt of the Niger Delta Basin

Petrophysical well logs were integrated in an analysis for the reservoir characterization of C and D wells located in the Offshore Depobelt of the Niger Delta Basin, Nigeria. The study essentially determined reservoir properties such as Lithology, shale volume, Porosity, hydrocarbon saturation and Net-Gross from Well logs with a  view to determining the Reservoir quality. Two lithologies were identified using Gamma ray and Resistivity logs which were sand and shale but minor presence of carbonate was encountered in well D at depth 5375-5380 feet. From the analysis, using the Resistivity log, all the eight (8) delineated reservoirs were identified as Hydrocarbon bearing unit (C1000-C8000). The porosity values ranged between 20-30 percent, indicating very good reservoir quality. Fluid types defined in the reservoir on the basis of Neutron/Density log signatures were basically water, oil and gas. Low water saturation in the reservoirs of the wells indicated that the proportion of void spaces occupied by water is low, thus indicating high Hydrocarbon Saturation. Average reservoir parameters such as porosity (32.5%), gross thickness (184.32 feet), Hydrocarbon Saturation (53.58℅) and Net-Gross (0.60 feet) were derived from the petrophysical analysis. The six reservoirs were ranked graphically using average result of petrophysical parameters. C2000 and C5000 are said to be the most producible while C6000 was the least producible within the study area. From these results, we can conclude the wells C and D are viable