Financial research concept

Proved Undeveloped Reserves: PUD Oil and Gas Inventory

Proved undeveloped reserves are proved oil and gas volumes expected to require new wells or significant future development spending before production.

By Lee BaileyPublished Sep 25, 2026

Research context

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Research date: Sep 25, 2026Use the dated article and cited sources for the definition, examples, and stated limitations.
Operating-model context: 18 connected conceptsPart of the reviewed Upstream E&P Economics; issuer definitions remain distinct where disclosed.
Company examples: 1 reviewed companyRelationships reflect supported examples, not a normalized cross-company KPI ranking.

EOG example
Five-year development context
Investor use
Source
Part of the Upstream E&P Economics
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Proved undeveloped reserves, commonly called PUDs, are proved oil and gas reserves expected to require new wells or significant additional development before production.

They are part of total Proved Reserves, but they carry a different capital and timing profile from proved developed reserves.

EOG example

EOG reported 2.168 billion BOE of PUDs at December 31, 2025, down by 14 MMBOE during the year.

The company added PUDs through drilling and reserve booking, acquired reserves, and converted a substantial volume of PUDs into proved developed reserves.

Five-year development context

Reserve rules generally require PUD development plans to support conversion within the applicable development horizon. EOG's reserve process includes a five-year development plan, and its auditor specifically describes testing forecasts for PUD conversion against drill plans and available capital.

Investor use

PUDs matter because they connect reserve inventory to future capital requirements.

A large PUD balance can represent a deep development inventory, but it can also imply substantial future spending. Pair PUD volume with future development costs, conversion pace, and expected economics.

Source

EOG Resources 2025 Form 10-K

Part of the Upstream E&P Economics

Connect realized pricing, per-BOE revenue and costs, reserve development, PUD conversion, and standardized reserve value to understand exploration and production economics.

Browse the full operating model in Company Analysis →

Where this concept fits

Reserve renewal, development capital, and standardized valueCurrent relationship
Reserve replacement and finding-and-development cost connect depletion with reserve renewal. Developed and undeveloped reserves show development status, PUD conversion volume and capital cost show execution, and future production and development costs feed the standardized discounted reserve-value calculation.
Finding and Development Cost Reserve Replacement Ratio Future Development Costs Future Production Costs Proved Developed ReservesProved Undeveloped ReservesCurrent conceptPUD Conversion Capital Cost PUD Conversion Volume Standardized Measure Discount Oil & Gas Standardized Measure
Commodity realizations and revenue per BOE
Crude and natural-gas benchmark differentials plus NGL realization relative to WTI show how market and location effects shape pricing, while composite operating revenue per BOE combines those realizations with production mix into one issuer-level revenue measure.
Operating Revenue per BOE Oil Realization Differential Gas Realization Differential NGL Realization % of WTI
Operating cost and per-unit profitability
Lifting cost frames field-level production expense, GP&T cost captures processing and delivery, and DD&A per BOE allocates capitalized asset costs across production. Composite operating income per BOE then shows the resulting issuer-defined per-unit operating profitability after the included cost base.
Lifting Cost Operating Income per BOE Upstream DD&A per BOE GP&T Cost per BOE

See It in Company Research

These companies are examples of how the concept is reported or discussed in public filings. Definitions can differ by issuer; these links open company research rather than a normalized metric comparison.

EOGOpen operating-model research →17 of 18 reviewed concepts in Upstream E&P EconomicsReserve renewal, development capital, and standardized value10 of 10 bridge concepts supportedContinue through this bridge:Finding and Development Cost Future Development Costs Future Production Costs Oil & Gas Standardized Measure Proved Developed Reserves PUD Conversion Capital Cost PUD Conversion Volume Reserve Replacement Ratio Standardized Measure Discount

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