Title: Process Simulation and Optimization of CO2 Removal from Niger Delta Natural Gas Using DEA in Aspen HYSYS
Authors: Victoria Akuchukwu Umejuru , Isaac Eze Ihua-Maduenyi
Volume: 10
Issue: 1
Pages: 116-125
Publication Date: 2026/01/28
Abstract:
The progressive decline in reservoir pressure and increasing water cut in mature Niger Delta oil wells have made the implementation of artificial lift systems essential to sustaining economic production. This study presents a comprehensive modelling and optimisation of well performance through nodal analysis and gas lift design, applied to a representative Niger Delta well using the PROSPER simulation environment. The methodology combines inflow performance relationship (IPR) modelling with vertical lift performance (VLP) analysis to characterise production system behaviour under both natural flow and gas-lifted conditions. Field data, including reservoir pressure, production rates, fluid properties, and completion parameters, were calibrated to establish a reliable base case model. Sensitivity analyses were conducted to investigate the impacts of gas injection rate, water cut, and reservoir pressure depletion on oil production efficiency. Under natural flow conditions, the well exhibited a maximum production of 1,150 STB/day at an average reservoir pressure of 2,800 psia, with deliverability declining sharply below 2,200 psia, resulting in unstable inflow-outflow matching. At a 40% water cut, oil production decreased by over 35%, highlighting the critical need for artificial lift support. Implementation of gas lift significantly improved production, with an optimised injection rate of 3 MMscf/day increasing oil output to 1,950 STB/day-a 69% improvement over natural flow. The optimised system maintained stable IPR-VLP intersections across a wide range of bottomhole pressures, ensuring sustainable drawdown and operational efficiency. Economic evaluation indicated that gas lift extended the productive life of the well by more than five years and increased the net present value (NPV) by approximately 30% relative to continued natural flow. These results demonstrate that gas lift is a technically robust and economically advantageous artificial lift strategy for pressure-depleted Niger Delta reservoirs. Furthermore, the integration of nodal analysis within PROSPER provides a reliable framework for production forecasting, optimisation, and informed decision-making in mature field development.