In this guide
What a working interest is
When a mineral owner leases their tract, they keep a royalty and grant the operating rights to someone else. Those operating rights are the working interest — the right to drill, complete and produce the wells, coupled with the obligation to fund every dollar it takes.
That pairing is the whole concept. A royalty owner has an income right. A working interest owner has a business: revenue on one side, an unbroken stream of costs on the other, and whatever is left over as the return. It is the only interest type that participates fully in a well's success, and the only one that can cost you money after you have already invested.
Working interest is not a synonym for "investment in a well." You can own exposure to a well through a royalty, an overriding royalty, a working interest, or a partnership unit — and the tax, liability and cash-flow profiles differ sharply. Establish which one a sponsor is actually offering before anything else.
Working interest vs. net revenue interest
This is the arithmetic every investor in this asset class should be able to do without help.
Your working interest (WI) is your share of the costs. Your net revenue interest (NRI) is your share of the revenue, after the royalty burden comes off the top. Because royalties are paid before working interest owners see anything, NRI is always lower than WI.
Worked example: a well is burdened by a 25% total royalty load — say a 20% landowner royalty plus a 5% overriding royalty to the geologist who assembled the deal. That leaves a 75% net revenue pool for the working interest owners. If you own a 10% working interest, you pay 10% of every cost and receive 7.5% of gross revenue (10% × 75%).
| Line | Figure |
|---|---|
| Your working interest (share of costs) | 10.0% |
| Landowner royalty | 20.0% |
| Overriding royalty | 5.0% |
| Net revenue pool to working interest | 75.0% |
| Your net revenue interest | 7.5% |
| Effective cost-to-revenue ratio | You fund 10% to earn 7.5% |
A deal quoted as "a 10% interest" that is silent on the royalty burden is missing the number that determines your return. Ask for the NRI in writing, and confirm it against the division order once production begins.
How it compares to other interests
| Working interest | Royalty interest | Overriding royalty (ORRI) | |
|---|---|---|---|
| Pays drilling & operating costs | Yes | No | No |
| Liability exposure | Yes — unlimited if held directly | None | None |
| Carved out of | The lease | The mineral estate | The working interest |
| Survives lease expiry | No | Yes — reverts to mineral owner | No |
| IDC deduction | Yes | No | No |
| Percentage depletion | Yes, 15% | Yes, 15% | Yes, 15% |
| Tax form | Schedule C | Schedule E | Schedule E |
The ORRI is worth understanding because it is frequently used as sponsor compensation: it is carved out of the working interest, meaning it reduces what investors receive, and it dies when the lease dies. If a promoter holds a large ORRI, they earn from production whether or not the investors ever recover their capital.
The costs you actually owe
- Drilling and completion. Estimated in advance on an AFE (authorization for expenditure). You approve it, then you are on the hook for your share — including overruns.
- Lease operating expenses (LOE). The monthly cost of keeping the well producing: labor, chemicals, power, water disposal, maintenance. Billed continuously for the life of the well.
- Joint interest billings (JIBs). The operator's monthly invoice for your proportionate share. Non-payment can trigger penalty provisions in the joint operating agreement, up to forfeiture of your interest.
- Workovers and recompletions. Periodic capital events. A single workover can exceed a year of net revenue on a marginal well.
- Plugging and abandonment. The end-of-life obligation to plug the wellbore and restore the site. It is real, it is proportionate to your interest, and it arrives when the well no longer generates income.
The obligation does not stop when the revenue does. A working interest in a well producing below its operating cost is a monthly bill, not an asset. This is the mechanism behind most genuinely bad outcomes in direct oil & gas investing — not a dry hole, but a marginal well nobody wants to plug.
Operated vs. non-operated
One party in a well serves as operator, conducting operations under a joint operating agreement (JOA). Everyone else holds a non-operated working interest: same proportionate costs, same proportionate revenue, no operational control.
Practically every investor-held working interest is non-operated, which makes the operator's competence and solvency a first-order concern rather than a footnote. A skilled operator on mediocre rock frequently outperforms a poor operator on good rock. Before committing, look at the operator's well results in that specific basin, their record on cost control against AFEs, and whether they are financially capable of meeting their own share of obligations. The basin analyses are a reasonable starting point for what good results look like in each play.
Liability, stated plainly
A working interest held directly, or through an entity that does not limit liability — a general partnership interest, for instance — carries unlimited, and typically joint and several, liability. Blowouts, surface contamination, injury claims and environmental remediation can in principle reach beyond the amount invested.
This is not a theoretical footnote; it is the defining economic feature of the interest, and it is precisely what buys the tax treatment described below. Most retail drilling programs are structured so investors hold general partner interests during the drilling phase, when IDC is generated, and then convert to limited partner interests once the wells are completed and the highest-risk window has closed. That conversion should be automatic in the partnership agreement. Verify it exists, verify the trigger, and separately verify the operator's insurance.
Why the tax treatment is different
The working interest receives the most favorable treatment in the asset class, for a specific reason: the tax code trades it against real risk.
- The passive-loss exception. Under IRC §469(c)(3), a working interest in oil or gas held directly or through an entity that does not limit the taxpayer's liability is not a passive activity — and, per IRS Publication 925, that holds whether or not you materially participated. The practical consequence is that losses can offset active income such as wages and business profit, which is the entire reason high earners look at these deals. Note the trap: if your liability becomes limited part-way through a year in which the well produced a net loss, some income and deductions can be recharacterized as passive.
- Intangible drilling costs. The non-salvageable portion of drilling cost — labor, fuel, fluids, site prep — is generally deductible in the year incurred under IRC §263(c) rather than capitalized. On a typical drilling investment, IDC commonly represents 65–80% of the outlay.
- Percentage depletion. Once producing, 15% of gross income from the property under the independent producer exemption in IRC §613A(c), subject to statutory limits.
- Self-employment tax. The cost of business treatment: an operating interest is reported on Schedule C, and net earnings are generally subject to self-employment tax — unlike royalty income on Schedule E.
The full mechanics, with worked examples and the AMT interaction, are in the tax benefits guide. The discipline worth repeating: run the economics at zero tax benefit first. A deduction defers character, it does not rescue a bad well.
How investors acquire one
There are three routes in practice. Most retail investors participate through a direct participation program — a drilling partnership that aggregates capital and holds the working interest, with investors as general or limited partners. Sophisticated investors sometimes purchase a non-operated working interest directly from an operator or in a secondary transaction, taking on the JOA obligations themselves. Rarely, an investor may farm in, funding a share of a well in exchange for an assignment of interest.
Each route carries the same underlying economics; what changes is the fee load and the governance. A DPP layers syndication costs, turnkey drilling margins and sponsor promotes on top of the well; a direct non-operated interest strips most of that out but requires you to underwrite and administer it yourself.
How to evaluate a working interest
- Get the NRI, in writing, alongside the working interest percentage. Confirm the total royalty burden including any overrides.
- Compare the AFE to actual well costs in that area. A turnkey price well above a realistic AFE is sponsor margin, not geology.
- Underwrite the operator — results, cost control, solvency, insurance.
- Model at a low price deck. If the deal only works at $85 oil, it is a commodity bet, not an investment.
- Read the JOA for non-consent penalties, default provisions and how plugging obligations are shared.
- Confirm the liability conversion mechanics if it is structured as a partnership.
- Understand the plugging liability and who carries it at the end of life.
This maps to the Structure, Economics and Risk-class tests in the RESERVES framework, and against the alternatives a working interest has to clear a high bar: it must beat a royalty (weigh that in are oil & gas royalties a good investment?) and an energy ETF after fees and after adjusting for the liability you are accepting.
The risks
Risk disclosure. Working interests are speculative and illiquid. Wells can be dry or underperform their type curve; costs can exceed estimates; commodity prices can fall sharply; a marginal well can generate ongoing net costs; plugging obligations survive the revenue; operators can become insolvent; and an interest held directly or as a general partner carries unlimited liability, meaning losses may exceed the amount invested. Tax outcomes depend on individual circumstances and structure and can change. This is educational content, not investment, tax or legal advice.
Stated more simply: the working interest is the only oil and gas interest that can ask you for more money after you have invested. That is not a reason to avoid it — it is the reason it earns better tax treatment and a bigger share of a good well. It is a reason to size the position as risk capital, verify the operator, and never buy one on the strength of a tax deduction alone.