Accounting for Risk in Oil and Gas Reserve Valuations

One of the most complex aspects of oil and gas valuation is accounting for the risk associated with proved developed nonproducing reserves (PDNP), proved undeveloped reserves (PUD), and the less certain probables and possibles (P2 and P3 Reserves).

When valuing proved developed producing reserves, estimates of future production, pricing, and expenses are based on historical results. However, production projections and expense forecasts are more speculative when it comes to PDNP reserves as they are not based on recent production history, and are even more abstract when it comes to PUD reserves since the wells have not yet been successfully drilled.

Accounting for Risk

Generally, there are three ways to account for the additional risk associated with PDNP, PUD reserves, probables, and possibles:

Using a risk-adjusted discount rate (RADR),
applying a reserve adjustment factor (RAF), or
utilizing a modified option pricing model.

In this post, we outline the basics of risk-adjusted discount rates and reserve adjustment factors. Some of the best guidance on measuring this risk is published by the Society of Petroleum Evaluation Engineers (SPEE). Every year at its annual meeting in June the SPEE presents the results to its annual survey to better understand the parameters used in property evaluation. The SPEE Survey is a global study, however, the majority of participants evaluate U.S. properties. The June 2018 survey had a total of 266 responses with over 80% of participants spending over half of their time evaluating U.S. properties. It covers a wide range of topics such as futures prices, costs and escalation, accounting for risk, reserve disclosures, and probabilistic methods. The survey presents the average RAF and RADR, as well as the 10^th percentile, 50^th percentile, and 90^th percentile results, based on the reserve type.

What are RADRs and RAFs?

A RADR is used to discount future cash flows to their present value while compensating for the additional risk associated with estimating future production from PDNP, PUD, P2, and P3 reserves. A RADR is higher than a discount rate used in a typical discounted cash flow analysis associated with companywide cash flows. Risk-adjusted discount rates generally fall within the range of 10% to 27%, according to the SPEE Annual Survey.

Reserve adjustment factors are applied to the present value of all future cash flows after a standard discount rate has been applied. RAFs vary widely; PDNP reserves generally have RAFs of 100% (no discount), while we have observed appraisals that have applied an RAF of 0% (implying a 100% discount) to PUD, P2, and P3 reserves.

There are many qualitative factors that should be considered when determining the appropriate RAF or RADR.

The current pricing environment. Is it economical to drill or start producing in the region given the current pricing environment for oil, natural gas, and NGLs?
Regional infrastructure issues. Is the necessary infrastructure in place to move products to market or is future production dependent upon increasing infrastructure out of the region?
Outlook/health of operators. For non-operators, there is additional risk associated with this relationship with a third party. Is the operator considering exiting the region due to the local drilling economics? Does the operator have enough capacity to bring new projects online? Is the operator financially stable or at risk of going out of business?

These are just some of the many pertinent questions to ask when analyzing the risk associated with PDNP and PUD reserves.

Applying a RAF or RADR

Generally the application of a RADR and RAF are interchangeable; however, it is important to avoid double counting risk when determining an appropriate discount rate to use in conjunction with a RAF.

The examples below show typical valuations of PUD reserves. The first applies the 50^th percentile result of the SPEE Survey for the reserve adjustment factor (60%) and the second uses the 50^th percentile result for the risk-adjusted discount rate (20%).

The results presented in the survey do not necessarily present reserve adjustment factors and risk-adjusted discount rates that compensate for the same level of risk, as shown by the lower valuation conclusion reached when using the RADR from the 50^th percentile. For a test of reasonableness, it is important to consider the implied risk-adjusted discount rate based on the selected RAF. In the example above, a 60% RAF is approximately equivalent to a 15.25% risk-adjusted discount rate.

Market Evidence for RAFs and RADRs

There is evidence in the public marketplace that undeveloped reserves are priced at a discount to their proven producing counterpart. For example, a recent acreage transaction in Gaines County was priced at a significantly lower acreage multiple than a transaction in Cochran County Texas, although the acreage was relatively close (only one county away). The acreage in Gaines County is in the Midland Basin, but the acreage in Cochran County is in the Northern Shelf; thus, in theory, the acreage in Gaines County is considered to be of higher quality. The acreage in Gaines County, however, consisted entirely of undeveloped acreage whereas the acreage in Cochran consisted of mostly producing acreage. The transaction of undeveloped acreage in Gaines County of the Midland Basin transacted at a 76% discount to acreage in Cochran County in the Northern Shelf, which equates to a reserve adjustment factor of 24%. While there are unique aspects of every transaction which make them hard to compare, there is a logical case to be made for the appropriateness of reserve adjustment factors and risk-adjusted discount rates. In the valuation profession, the most commonly used standard of value is “fair market value” which is defined as:

The price, expressed in terms of cash equivalents, at which property would change hands between a hypothetical willing and able buyer and a hypothetical willing and able seller, acting at arm’s length in an open and unrestricted market, when neither is under compulsion to buy or sell and when both have reasonable knowledge of the relevant facts.^[1]

A hypothetical investor would weigh the risks associated with the development of PUD reserves and would consider an investment in these assets to be inherently riskier than an investment in PDP reserves. As valuation professionals, we account for this risk by application of a RADR or RAF.

Mercer Capital has significant experience valuing assets and companies in the energy industry, primarily oil and gas, biofuels, and other minerals. Our oil and gas valuations have been reviewed and relied on by buyers and sellers and Big 4 Auditors. These oil and gas related valuations have been utilized to support valuations for IRS Estate and Gift Tax, GAAP accounting, and litigation purposes. We have performed oil and gas valuations and associated oil and gas reserves domestically throughout the United States and in foreign countries. Contact a Mercer Capital professional today to discuss your valuation needs in confidence.

[1] American Society of Appraisers, ASA Business Valuation Standards (Revision published November 2009), “Definitions,” p. 27.

Haynesville Shale M&A Update: 2025 in Review

Key TakeawaysHaynesville remains a strategic LNG-linked basin. 2025 transactions emphasized long-duration natural gas exposure and proximity to Gulf Coast export infrastructure, reinforcing the basin’s importance in meeting global LNG demand.International utilities drove much of the activity. Japanese power and gas companies pursued direct upstream ownership, signaling a shift from traditional offtake agreements toward greater control over U.S. gas supply.M&A was selective but meaningful in scale and intent. While overall deal volume was limited, announced transactions and reported negotiations reflected deliberate, long-term positioning rather than opportunistic shale consolidation.OverviewM&A activity in the Haynesville Shale during 2025 was marked by strategic, LNG-linked transactions and renewed international investor interest in U.S. natural gas assets. While investors remained selective relative to prior shale upcycles, transactions that did occur reflected a clear pattern: buyers focused on long-duration gas exposure, scale, and proximity to Gulf Coast export markets rather than short-term development upside.Producers and capital providers increasingly refocused efforts on the Haynesville basin during the year, including raising capital to acquire both operating assets and mineral positions. This renewed attention followed a period of subdued transaction activity and underscored the basin’s continued relevance within global natural gas portfolios.Although the Haynesville did not experience the breadth of consolidation seen in some oil-weighted plays, the size, counterparties, and strategic motivations behind 2025 transactions reinforced the basin’s role as a long-term supply source for LNG-linked demand.Announced Upstream TransactionsTokyo Gas (TG Natural Resources) / ChevronIn April 2025, Tokyo Gas Co., through its U.S. joint venture TG Natural Resources, entered into an agreement to acquire a 70% interest in Chevron’s East Texas natural gas assets for $525 million. The assets include significant Haynesville exposure and were acquired through a combination of cash consideration and capital commitments.The transaction was characterized as part of Tokyo Gas’s broader strategy to secure long-term U.S. natural gas supply and expand its upstream footprint. The deal reflects a growing trend among international utilities to obtain direct exposure to U.S. shale gas through ownership interests rather than relying solely on long-term offtake contracts or third-party supply arrangements.From an M&A perspective, the transaction highlights continued willingness among major operators to monetize non-core or minority positions while retaining operational involvement, and it underscores the Haynesville’s attractiveness to buyers with a long-term, strategic view of gas demand.JERA / Williams & GEP Haynesville IIIn October 2025, JERA Co., Japan’s largest power generator, announced an agreement to acquire Haynesville shale gas production assets from Williams Companies and GEP Haynesville II, a joint venture between GeoSouthern Energy and Blackstone. The transaction was valued at approximately $1.5 billion.This acquisition marked JERA’s first direct investment in U.S. shale gas production, representing a notable expansion of the company’s upstream exposure and reinforcing JERA’s interest in securing supply from regions with strong connectivity to U.S. LNG export infrastructure.This transaction further illustrates the appeal of the Haynesville to international buyers seeking stable, scalable gas assets and highlights the role of upstream M&A as a tool for portfolio diversification among global utilities and energy companies.Reported Negotiations (Not Announced)Mitsubishi / Aethon Energy ManagementIn June 2025, Reuters reported that Mitsubishi Corp. was in discussions to acquire Aethon Energy Management, a privately held operator with substantial Haynesville production and midstream assets. The potential transaction was reported to be valued at approximately $8 billion, though Reuters emphasized that talks were ongoing and that no deal had been finalized at the time.While the transaction was not announced during 2025, the reported discussions were notable for both their scale and the identity of the potential buyer. Aethon has long been viewed as one of the largest private platforms in the Haynesville, and any transaction involving the company would represent a significant consolidation event within the basin.The reported talks underscored the depth of international interest in Haynesville-oriented platforms and highlighted the potential for large-scale transactions even in an otherwise measured M&A environment.ConclusionWhile overall deal volume remained selective, the transactions and reported negotiations in 2025 reflected sustained global interest in U.S. natural gas assets with long-term relevance. Collectively, the transactions and negotiations discussed above point to a Haynesville M&A landscape driven less by opportunistic consolidation and more by deliberate, long-term positioning. As global energy portfolios continue to evolve, the Haynesville basin remains a focal point for strategic investment, particularly for buyers seeking exposure tied to U.S. natural gas supply and LNG export linkages.

Accounting for Risk in Oil and Gas Reserve Valuations

Reserve Adjustment Factors and Risk-Adjusted Discount Rates