Integrated Modelling and Reservoir Characterization of Ataga Field, Niger Delta Basin, Nigeria

Abstract

Integrated modelling, well correlation and petrophysical analysis were performed to characterize the reservoirs for optimum hydrocarbon correlation using 3-D seismic reflection data and suites of well logs from Ataga 5, 7, 10 and 11 wells respectively in Ataga field, shallow offshore, Niger Delta Basin, Nigeria. The study revealed the presence of two viable hydrocarbon bearing reservoirs, AT1 and AT2 and the average values of porosity, permeability, water saturation, hydrocarbon saturation, Net to Gross (NTG) and volume of shale are in the ranges of 15% - 77%, 44.5% - 75.5%, 25.5% - 85%, 15% - 75.5%, 0.70 - 0.88 and 0.11 - 0.38 respectively which goes further to show that the both reservoirs have fair characteristics that are suggestive of the presence of hydrocarbon accumulation. It can therefore be deduced that the permeability values are reflective of fair interconnectivity of pore spaces of sands within the well areas and their ability to transmit fluids, the depth and depth structural map generated for the horizons and structures shows that the most dominant trapping mechanism in the area under study is the crescentic growth fault and the rollover anticlines trending in the Northwest-Southeast direction and from the volumetric analysis. It can be deduced that the recoverable gas for AT1 and AT2 reservoirs is 2 × 10 6 mscf and 6 × 10 6 mscf respectively.