MATERIAL BALANCE ANALYSIS OF A SATURATED OIL RESERVOIR IN AN ONSHORE NIGER DELTA FIELD

In the petroleum industry, the accurate determination of hydrocarbons initially in place is critical for effective reservoir management and the formulation of efficient production strategies. This research focuses on the evaluation of a saturated oil reservoir in an onshore Niger Delta field through the application of Material Balance Analysis (MBA). The objectives of the study include estimating the initial oil in place, evaluating the presence and strength of an underlying aquifer, identifying the dominant reservoir drive mechanism, and recommending an optimal production scheme capable of maximizing economic recovery. For this research, the majority of the reservoir and production data were obtained from Nigerian National Petroleum Company (NNPC), which also provided access to the MBAL simulation software. MBAL is a simplified yet powerful analytical tool that applies the concept of material balance to characterize reservoir behavior. The program models the reservoir using a zero-dimensional (tank) approach, which does not explicitly account for geometry, drainage area, or well orientation, but provides valuable insights into fluid distribution and drive mechanisms by analyzing production and pressure performance. The results from the MBAL analysis indicate that the reservoir contains an estimated 250.258 MMSTB of oil initially in place, and the predicted volume of water in place to be 99788.4 MMft3 . Furthermore, the aquifer’s influence on reservoir pressure performance demonstrates that water drive is the predominant drive mechanism sustaining production. These findings provide a reliable basis for planning production strategies that optimize reservoir performance while enhancing ultimate recovery. In carrying out this research, valuable hands-on experience was gained in data handling, diagnostic plotting, and MBAL simulation. The work strengthened descriptive, technical and analytical competence in reservoir evaluation and provided deeper insight into the importance of accurate data interpretation for sustainable hydrocarbon recovery in the Niger Delta basin.