Production Operations
Production operations begin once wells have been drilled, completed, and connected to surface facilities. This phase is where the investment in exploration and development finally generates revenue. In Nigeria, production operations manage the flow of crude oil and natural gas from thousands of wells spread across onshore fields, swamp locations, offshore platforms, and deepwater floating facilities.
Wellhead to Flow Station
At the wellhead, a system of valves known as the "Christmas tree" controls the flow of hydrocarbons from the well. The produced fluid - a mixture of crude oil, natural gas, water, and sediment - flows through gathering flowlines to a central collection point called a flow station. In Nigeria's onshore and swamp operations, a single flow station typically receives production from 20 to 50 wells via a network of flowlines.
Well Testing & Allocation
Each well is periodically routed through a test separator to measure its individual flow rate of oil, gas, and water. This data is used to allocate total flow station production back to individual wells and to monitor well performance over time.
Manifold & Header System
Wells are connected to manifolds that combine production from multiple wells. High-pressure and low-pressure headers separate wells based on their flowing pressures, ensuring efficient processing and preventing back-pressure on lower-pressure wells.
Crude Oil Processing
At the flow station, the raw produced fluid undergoes several stages of processing to separate oil, gas, and water:
Separation
Production separators use gravity and pressure reduction to separate the three phases. Most Nigerian flow stations use two or three stages of separation - high pressure, intermediate, and low pressure - to maximise oil recovery and stabilise the crude.
Dehydration & Desalting
Crude oil typically contains emulsified water and dissolved salts that must be removed before export. Electrostatic heater-treaters break water-in-oil emulsions, and desalting units reduce salt content to meet export specifications (typically below 10 pounds per thousand barrels).
Storage & Metering
Processed crude is stored in tank farms before being pumped into export pipelines or loaded onto tankers. Fiscal metering systems accurately measure the volume and quality of crude for royalty and tax purposes. Custody transfer meters at export terminals are calibrated to strict standards.
Export Pipeline Network
Processed crude flows through trunk lines to coastal export terminals. Major trunk lines include the Trans-Niger Pipeline (to Bonny Terminal), the Nembe Creek Trunk Line, and the Trans Forcados Pipeline. These pipelines are frequently targeted by vandals and oil thieves.
Water Handling
As Nigerian oil fields mature, water production increases significantly. Some older fields produce over 80% water (known as high water cut), meaning that for every barrel of oil, four or more barrels of water must be handled. Produced water contains traces of oil, dissolved minerals, and sometimes naturally occurring radioactive materials (NORM). It must be treated before disposal or re-injection.
Water treatment facilities at flow stations use corrugated plate interceptors (CPIs), flotation units, and filters to remove oil from produced water. Treated water is either re-injected into the reservoir (for pressure maintenance and improved recovery) or discharged in compliance with Department of Petroleum Resources (now NUPRC) effluent standards.
Gas Handling
Associated gas - natural gas produced alongside crude oil - has historically been a challenge in Nigeria. For decades, much of it was flared (burned at the wellsite), making Nigeria one of the world's largest gas flaring nations. Government regulations and commercial incentives have progressively reduced flaring:
Gas Re-injection
Compressing and injecting gas back into the reservoir to maintain pressure and enhance oil recovery. This is widely practised in Nigeria and is mandated where technically feasible.
Gas-to-Power
Some operators use associated gas to fuel on-site power generation or supply gas to nearby power plants, contributing to Nigeria's electricity supply while reducing flaring.
Gas Gathering & Processing
Networks of gas gathering pipelines transport associated gas from flow stations to gas processing plants, where it is treated and fed into the domestic gas market or the Nigeria LNG plant on Bonny Island.
Production Monitoring & Surveillance
Operators continuously monitor production performance using a combination of surface and downhole measurements. Key surveillance activities include daily production rate tracking, regular well tests, reservoir pressure surveys, and production logging. Modern Nigerian operations increasingly use real-time data from downhole gauges transmitted to control rooms, enabling faster response to changing well conditions.
Major Nigerian Export Terminals
| Terminal | Location | Operator | Capacity (bpd) | Crude Grades |
|---|---|---|---|---|
| Bonny Terminal | Bonny Island, Rivers | SPDC JV | ~450,000 | Bonny Light |
| Forcados Terminal | Delta State | SPDC JV | ~400,000 | Forcados Blend |
| Brass Terminal | Bayelsa State | ENI/NAOC JV | ~200,000 | Brass River |
| Escravos Terminal | Delta State | CNL/Chevron JV | ~310,000 | Escravos Blend |
| Qua Iboe Terminal | Akwa Ibom State | MPN (ExxonMobil) JV | ~400,000 | Qua Iboe |
| Pennington Terminal | Delta State | CNL/Chevron JV | ~160,000 | Pennington Light |
Sources
- NNPC, "Monthly Petroleum Information" (terminal throughput data).
- NUPRC, "Production Data and Crude Oil Export Statistics".