Reserve based lending explained

Reserve based lending is a revolving bank facility for upstream oil and gas exploration and production companies in which availability is limited by a borrowing base derived from an engineering valuation of proved reserves, typically secured by a first lien on those reserves and their cash flow.

The United States Office of the Comptroller of the Currency (OCC) describes reserve based loans (RBLs) as the financing form used by most independent, non integrated exploration and production companies. The RBL is typically a revolving facility secured by lower risk proved reserves and governed by a borrowing base determined by a valuation of those reserves. Most RBLs have a term of three to five years. The stated purpose is primarily to fund acquisition and development costs for new reserves which, if successful, increase reserve valuations and cash flow for debt service.

How the borrowing base is set

The borrowing base is the lending commitment established from the engineering valuation of the borrower's proved oil and gas reserves, subject to limitations and adjustments. It is determined by analysing previous production reports and independent engineering evaluations. Commodity prices, risk adjustment factors and the cash flow discount rate used to determine reserve values must be supported in the lender's underwriting documentation.

OCC guidance states that banks typically perfect liens on reserve interests that produce 75 percent to 90 percent of the economic value of the borrowing base. The outstanding balance fluctuates with draws and repayments, but cannot exceed the lower of the facility commitment and the then current borrowing base.

Lenders generally use risk adjustment factors to lower the value of unseasoned producing and nonproducing reserves before applying advance rates. Frequently used factors cited by the OCC include 100 percent of seasoned proved developed producing (PDP) reserves, 90 to 95 percent of unseasoned PDP, 65 to 75 percent of proved developed nonproducing (PDNP), and 25 to 50 percent of proved undeveloped (PUD) reserves. Banks then typically apply a single advance rate to total risk adjusted proved reserves. Maximum advance rates against the total risk adjusted net present value commonly range between 50 and 65 percent. Unproved reserves are generally excluded because recovery is less certain.

Reserve based lending redeterminations and monitoring

The borrowing base is normally reset every six months. The bank reviews the most recent engineering reserve report and applies its methodology to reset the commitment. Redeterminations typically occur semiannually, with additional redetermination rights often available once or twice a year as defined in the credit agreement. Price decks used in valuation should be updated at least semiannually, or more frequently when markets move sharply.

If the borrowing base falls below the outstanding balance, the credit agreement sets repayment criteria to eliminate the excess. Declining commodity prices can reduce revenues, constrain production growth and cut borrowing bases at redetermination. Covenant packages commonly include leverage, current ratio and interest coverage tests. Some facilities define the current ratio to include unfunded RBL availability.

Independent engineering capacity is a control expectation. OCC material stresses that the oil and gas engineering function should be independent of loan production and credit approval, that compensation should not incentivise loan volume, and that staffing should support timely semiannual redeterminations.

Security, repayment and distinction from project finance

The RBL is normally secured by a first lien on the borrower's oil and gas reserves, with cash flow from production as the primary repayment source and liquidation of reserves as a secondary source. Other senior notes or bonds are normally subordinate in collateral position, although second lien structures can be pari passu in contractual payment rights in some cases.

Reserve based lending is a borrowing base corporate facility tied to a reserve portfolio, not a single asset limited recourse project finance loan sized solely on one field's contracted cash flows and a DSCR grid. Project finance may still be used for midstream, LNG or large field developments with dedicated offtake. Upstream RBL credit instead tracks proved reserve value, production history, hedging and redetermination mechanics across a collateral package.

Hedging policies, concentration limits by well or field, and limits on nonproducing reserves in the borrowing base are standard underwriting controls. Stretch borrowing bases that use higher advance rates or more aggressive inclusion of PDNP and PUD reserves are treated as exceptions requiring clear approval and pricing.

OCC guidance notes that stretch decisions may include higher advance rates over 65 percent, less conservative risk factors, or giving value for the next six months of production that is usually omitted. Approval of a stretched borrowing base should not be used merely to avoid borrower repayment when the conforming base has fallen. Some structures split conforming and nonconforming stretch tranches with higher fees and rates on the stretch loans.

Export finance and official support overlap

Upstream producers and associated export infrastructure can intersect with official export credit where equipment supply or project exports are involved. An export credit agency may support eligible export contracts or, in some jurisdictions, untied loan guarantees for raw material projects. German federal materials describe untied loan guarantees as support for eligible raw material projects abroad. Those products follow separate eligibility and OECD rules. They do not redefine an RBL borrowing base, which remains a commercial bank valuation of proved reserves.

Berne Union membership lists the major official and private credit insurers active in trade and investment insurance markets. Their presence in a capital structure is product specific. An RBL remains a reserve secured revolving facility whether or not an export credit instrument sits elsewhere in a sponsor group financing plan.

Credit boundaries

Reserve based lending does not convert probable or possible reserves into borrowing base collateral by label alone. Proved reserves are quantities reasonably certain to be commercially recoverable under current economic conditions, operating methods and government regulations. Probabilistic methods associate proved reserves with at least a 90 percent probability that actual recovery will equal or exceed the estimate. Loan underwriting is predicated primarily on PDP reserves.

Mezzanine debt may fund development when producing reserves are insufficient to support RBL capacity. Those loans are generally not borrowing base facilities and sit behind senior RBL claims.

Reserve based lending is therefore a proved reserve borrowing base revolver for upstream producers, redetermined on engineering and price assumptions, secured by reserve cash flows, and distinct from single asset project finance even where both appear in energy sector credit portfolios.