The Economics of Marginal Fields: Making Small Oil Fields Pay in Nigeria
Anslem Oshionebo on what makes Nigeria's marginal oil fields commercially viable: costs, evacuation, financing, partnerships and fiscal terms.

Nigeria's marginal fields are discovered accumulations that larger operators did not prioritise, often because they were small, remote or technically challenging. The 2020 marginal field bid round awarded dozens of fields to more than 150 Nigerian companies. Turning those awards into production is a lesson in upstream economics: small fields only pay when every element of cost and risk is managed tightly.
Why small fields are hard
- Scale: fixed costs for facilities, evacuation and compliance weigh heavily on limited reserves.
- Evacuation: getting crude to an export terminal can be the largest single cost and risk.
- Data: legacy data may be limited, raising subsurface uncertainty.
- Financing: lenders are cautious with small, single-asset companies.
What makes them pay
- Phased development: start with low-cost early production to generate cash and data.
- Shared infrastructure: cluster developments and shared processing or evacuation cut unit costs.
- Modular facilities: leased or modular processing units reduce upfront capital.
- Partnerships: technical partners and financiers who bring experience as well as money.
- Cost discipline: every dollar per barrel matters when volumes are small.
Modelling the economics
A credible model tests reserves, production profiles, capital and operating costs, evacuation tariffs, royalties and taxes under the Petroleum Industry Act, and a range of oil prices. The key outputs are breakeven price, payback period, net present value and peak funding need. If the field works at conservative prices with realistic costs, it is financeable.
Key numbers in a marginal field model
- Recoverable reserves: often a few million to tens of millions of barrels.
- Development cost per barrel: wells, facilities and evacuation divided by reserves.
- Operating cost per barrel: staff, maintenance, chemicals, security and tariffs.
- Fiscal take: royalties, taxes and other government payments under the applicable regime.
- Breakeven price: the oil price at which the project returns its cost of capital.
A project with a breakeven well below expected prices has room to absorb delays and cost overruns. One that only works at high prices is a speculative bet.
The 2020 marginal field round
Nigeria's 2020 marginal field bid round awarded dozens of fields to indigenous companies. It showed strong local appetite for upstream assets and highlighted the challenges that follow award: raising development finance, securing technical partners, agreeing evacuation and meeting regulatory timelines. Companies that combined technical teams with financial structuring moved fastest.
Ways to reduce costs
- Use existing wells for early production where possible.
- Lease or share facilities with neighbouring fields.
- Use modular, relocatable processing units.
- Cluster evacuation with nearby operators to share pipeline or barging costs.
- Contract services on performance-based terms.
A leader's view: discipline decides the outcome
Marginal fields test leadership more than geology. The reservoir is usually known; the question is whether the team can develop it on budget, on time and with reliable evacuation. That requires discipline in several areas at once.
Capital discipline: commit money in stages tied to results. Early production should fund later phases where possible, reducing dependence on expensive external capital.
Contract discipline: choose service providers with clear scopes, performance terms and accountability for delays. Small projects cannot absorb large overruns.
Operational discipline: track cost per barrel weekly, not quarterly. Investigate every variance and act on it.
Stakeholder discipline: keep regulators, partners, lenders and host communities informed. Surprises damage trust and slow approvals.
Financing is often the hardest step. Lenders will want certified reserves, a credible operator, firm evacuation arrangements and a model that survives lower prices. Sponsors who present those elements clearly, with realistic assumptions and contingency, attract better terms. Marginal fields remain one of the best entry points into Nigerian upstream for capable indigenous companies. With the right combination of technical and financial skill, small fields can build large businesses and create jobs and capability for the country.
The opportunity
Marginal fields can add meaningful production, create Nigerian jobs and build a generation of indigenous operators. Success depends on the combination of engineering judgment and financial discipline that defines good upstream investing.
Common questions
What is a marginal oil field in Nigeria?
A smaller discovered field that a larger licence holder did not prioritise for development, often awarded to indigenous companies to develop.
How can marginal fields be profitable?
Through phased development, low-cost and shared facilities, reliable evacuation, experienced partners and close control of cost per barrel.