Carried Working Interest: Definition, Farmout, and Petroleum Finance

A carried working interest (CWI) is a contractual arrangement in petroleum exploration and production whereby one working interest owner, called the carried party, has some or all of its share of drilling and completion costs paid by another party, called the carrying party, up to a defined contractual milestone. In return for absorbing those costs, the carrying party typically receives a working interest in the prospect, access to geological data or technical work product, or both. The carried party retains its working interest in the well or licence and, once the carry obligation is discharged, participates in production revenues according to its equity share. Carried interest arrangements are a primary mechanism through which exploration risk is allocated, capital is recycled across the industry, and smaller technical companies gain entry into drilling programmes they could not fund unilaterally. They are foundational to understanding how joint ventures, farmout agreements, and exploration finance work across every major hydrocarbon province in the world.

Key Takeaways

• A carried working interest allows the carried party to retain its equity share in a prospect without contributing cash to drilling costs up to the agreed carry point; the carrying party advances those costs and recovers them from production or, in some structures, from the carried party's revenue stream after payout.
• The three principal carry structures are: carried to casing point (least risk for the carrier, ends at the decision to complete or abandon); carried through completion (carrier pays through full well completion); and carried through payout (most comprehensive, carrier funds everything until revenues recover the carried costs plus any agreed premium).
• A promote is the premium embedded in a carry arrangement when the carrying party funds more than its proportionate share of well costs, effectively acquiring the exploration upside at a cost above its equity fraction, in exchange for the technical contribution or data provided by the carried party.
• Carried interest arrangements most commonly arise in farmout agreements, where the farmor (landowner or licence holder) transfers a working interest to the farmee in exchange for a drilling carry on the retained interest, though CWI structures also appear in joint operating agreements (JOAs), asset swap deals, and corporate joint ventures.
• International petroleum agreements, including production sharing contracts (PSCs) and concession agreements, frequently incorporate carry provisions that allow national oil companies (NOCs) to participate in exploration upside after commercial discovery without bearing pre-discovery risk, a structure sometimes called a "back-in right" or "state carry."

How a Carried Working Interest Works

The fundamental mechanics of a carried working interest begin with a joint venture between at least two parties holding working interests in a licence or lease. When a decision is made to drill an exploration or development well, each working interest owner is ordinarily responsible for its proportionate share of costs, as stipulated by the joint operating agreement and the authority for expenditure (AFE) or authority for expenditure. A carry arrangement modifies this default: the carrying party agrees to pay not only its own share but also all or part of the carried party's share, advancing those funds on behalf of the carried party. The carrying party's total financial exposure therefore exceeds its equity percentage.

The carry period has a defined endpoint negotiated contractually. The most common endpoints are casing point, completion, and payout. At casing point, surface and intermediate casing strings have been run and cemented; the well has been drilled to total depth (TD) and evaluated, and the parties face a decision to attempt completion or plug and abandon. Ending the carry at casing point means the carrier has borne all drilling risk but the carried party must fund its share of completion costs (perforating, stimulation, tubing, wellhead) if it elects to participate. In a carried-through-completion arrangement, the carrier also pays the carried party's completion costs. In a carried-through-payout arrangement, the carrier continues advancing the carried party's share of all well costs (and sometimes gathering, processing, and tie-in costs) until cumulative production revenues attributable to the carried party's working interest have fully repaid the carrier. The carried party therefore has zero cash outflow until payout, after which it receives its full revenue share.

Recovery of carried costs typically follows one of two mechanisms. In a non-recourse carry, the carrier recovers its advanced costs solely from the carried party's share of production revenues; if the well is dry or sub-commercial, the carrier bears the loss entirely and has no recourse against the carried party's other assets. In a recourse carry, the advanced costs become a debt obligation of the carried party, repayable from revenues or from other assets if production is insufficient. Non-recourse carries are far more common in exploration arrangements because they align the carrier's financial exposure with the geological outcome, preserving the risk-sharing logic that makes carried interest an effective exploration finance tool.

The Promote: Pricing the Carry

When a carried working interest is established in exchange for geological or technical work rather than for cash, the arrangement implicitly includes a promote. The promote is the portion of well costs that the carrying party funds in excess of its proportionate working interest share. For example, if a carrying party holds a 50 percent working interest and agrees to pay 75 percent of well costs while carrying the remaining 25 percent owner (the carried party) through completion, the carrying party is paying 50 percent of its own share plus 25 percent of the carried party's share, totalling 75 percent of total well cost against a 50 percent equity. The excess 25 percent represents the promote paid by the carrier to acquire the technical contribution, data package, or prospect access that the carried party brought to the deal.

Promotes are expressed in various ways in industry practice. A "one-third for one-quarter" promote, common in US independents, means the carrying party pays one-third (33.3 percent) of the well costs to earn a one-quarter (25 percent) working interest, implying the 75 percent owner carried the 25 percent party through the well while also bearing the proportionate exploration risk. Promotes are effectively the price of geological knowledge, prospect access, or seismic data in a market where those intangibles lack a transparent exchange-listed value. In competitive bidding environments such as Gulf of Mexico deepwater licence rounds, promote structures help internalize the value of technical superiority without requiring explicit cash payments for data.

From a project economics standpoint, a carried party accepting a promote is trading a higher present-value cost (the promote foregone on the well) for certainty of retained upside without the downside cash exposure. For a small technical company with limited capital but high-quality prospect inventory, this trade can generate substantially higher risk-adjusted returns than self-funding a diversified but undercapitalized drilling programme.

Farmout Agreements and Their Relationship to Carried Interest

The farmout agreement is the transaction document most frequently associated with carried working interests, though the two concepts are legally distinct. A farmout is an agreement in which the holder of a working interest (the farmor) assigns some or all of that interest to another party (the farmee) in exchange for the farmee agreeing to undertake a drilling obligation or other work programme. The farmee "earns" the assigned interest by fulfilling the work commitment. A carry is the mechanism by which the farmor's retained interest (if any) is funded during the earn-in period. Specifically, the farmor may retain a carried working interest, meaning its proportionate share of drilling costs on the earn-in well is paid by the farmee as part of the consideration for the assignment.

A classic farmout structure works as follows: the farmor holds a 100 percent working interest in a licence block with a drilling obligation it cannot fund. The farmee agrees to drill one well in exchange for earning 75 percent of the working interest. The farmor retains 25 percent, carried through the earn-in well. The farmee pays 100 percent of well costs (its 75 percent share plus the farmor's 25 percent share) to earn its 75 percent interest. After the earn-in well is drilled to casing point (or completion or payout, depending on the carry depth), costs revert to working interest proportions: farmee 75 percent, farmor 25 percent. If the well discovers commercial crude oil or natural gas, both parties benefit; if it is dry, the farmee has borne 100 percent of the dry-hole cost and earned a 75 percent interest in an un-drilled block.

Farmout agreements also commonly include drilling obligations on multiple wells, phased earn-in structures (the farmee earns a partial interest on each well drilled), reversion rights (the farmor's interest reverts to a higher percentage if certain production thresholds are not met), and area of mutual interest (AMI) clauses (requiring parties to offer each other participation rights on any new acreage acquired within a defined area). Each of these provisions interacts with the carry mechanics and must be precisely defined in the agreement to avoid disputes over cost allocation and interest reversion.

Back-In Rights and State Carry Structures

A back-in right is an option, held by one party to a joint venture, to elect participation in production after a defined triggering event, most commonly commercial discovery or completion of a development plan. Back-in rights are especially common in arrangements where the national oil company (NOC) of the host country participates in an exploration block without contributing to pre-discovery exploration costs. The IOC carries the NOC through the exploration phase; upon discovery, the NOC exercises its back-in right to take its contracted working interest (commonly 15-25 percent, though higher in some jurisdictions) in the development project, contributing its proportionate share of development capital from that point forward. The IOC recovers its carried exploration costs either through a gross-up of the NOC's working interest during payout or through a negotiated cash reimbursement at the time of back-in election.

State carry structures exist in production sharing contracts (PSCs) throughout the world. Under a typical PSC, the contractor (IOC) bears all exploration risk. If no commercial discovery is made, the contractor loses its investment and the acreage reverts to the state. If a discovery is made and declared commercial, the state (through its NOC) exercises its right to participate in the development at a pre-agreed working interest, backed-in at no cost or at cost, depending on the specific terms of the PSC. Carried through payout provisions ensure the IOC recoups its exploration and appraisal investment from the state's share of production (cost oil) before full proportionate revenue splits apply. This structure transfers exploration risk to private capital while preserving state sovereignty over commercial reserves.