ONWUBOLU ESUMEL RAYMOND

This study presents an integrated production-optimization assessment of a mature, high-water-cut reservoir in the Niger Delta. The aim was to evaluate and compare artificial-lift strategies and system-level interventions to restore economic oil production and extend field life. A validated modeling workflow coupling MBAL (material-balance), PROSPER (well performance and artificial-lift design) and GAP (surface-network optimization) was developed and history-matched to 1987–2004 field data, revealing strong aquifer support and persistent water cuts (~80%). Scenarios examined natural flow, gas lift, and electric submersible pump (ESP) implementations with nodal and sensitivity analyses (IPR/VLP matching, PVT calibration, and network constraints). Results show natural flow is insufficient under present conditions; gas lift yields modest gains (≈720 STB/day total liquid, ~144–177 bbls oil/day) with moderate gas requirements, while ESPs can deliver substantially higher liquid and oil rates (pump-design rates up to ~3,800–4,300 RB/day and oil production improvements), albeit with higher power, gas-handling, and reliability considerations. Integrated GAP analysis highlights surface constraints and water-handling costs as decisive economic drivers. Recommendations include staged pilot deployment (ESP where power and conditions permit; gas lift where gas is abundant), targeted diagnostics and zonal shut-off, surface-network upgrades, and ongoing model re-calibration. The study demonstrates the value of coupled reservoir–well–surface workflows for optimizing mature, high-water-cut assets.