Abstract
This work integrates seismic and well log data to establish a 3D reservoir model of the Q-Field, which is a prolific onshore hydrocarbon field situated in the Central Swamp Depobelt of Nigeria. The subsurface modeling focuses on the four principal clastic reservoir intervals of the Agbada Formation (D6200, D7000, D9000 and E2000), which was deposited in a deltaic to fluvio-deltaic system during Eocene. The seismic-based structural modeling inferred an extensional set-up dominated by NW-SE trending normal faults. Reservoirs are sand-dominated and laterally extensive, as interpreted from the 3D facies model. Well log-based petrophysical parameters were up-scaled and distributed stochastically using the Sequential Gaussian Simulation method to generate a 3D reservoir property model. Lateral and vertical heterogeneities of the reservoir properties were inferred from the 3D models. In general, the clastic reservoirs exhibit 18-22% porosity, 62-105 mD permeability, moderate to good net-gross thickness, and 36-74% water saturation. Hydrocarbon accumulation was primarily restricted within the anticlines. Gas-down-to exists in the upper three reservoirs (D6200, D7000 and D9000) at 10,577 ft (1 ft = 0.3048 m), 10,756 ft and 11,389 ft, respectively. Gas-oil and oil-water contacts in the E2000 reservoir were interpreted to be at 11,812 ft and 11,886 ft, respectively. Based on the hydrocarbon distribution, oil and gas-in-place volumes were estimated for all the reservoir intervals. The comprehensive 3D modeling work addressed the spatial distribution of the studied reservoir properties and can be directly useful for planning better the future wells for field development.