What it is
Estimated Ultimate Recovery (EUR) is the total volume of hydrocarbons — typically quoted in barrels of oil equivalent (BOE) or MMcf of gas — that is expected to be produced from a well, field, or reservoir over its productive life, under defined economic and operating conditions.
EUR is particularly central to unconventional petroleum economics, where individual horizontal wells have well-defined EUR distributions that operators use to build type curves, plan infill spacing, and evaluate acquisition targets.
How it's calculated
- Decline curve analysis. Historic production fit to an Arps or hyperbolic decline, extrapolated to economic limit.
- Volumetric methods. Reservoir volume × recovery factor, for conventional reservoirs with sufficient data.
- Analogy. Based on nearby wells in the same rock, using type curves.
- Probabilistic / simulation. For resource declarations under PRMS, JORC, or NI 43-101.
Why it matters for pre-drill workflows
In unconventional development, the single most consequential decision is where to land the horizontal — because identical wells at nearby locations can deliver materially different EURs. Pre-drill substance characterization that identifies the sweet-spot intervals within a bench directly targets higher-EUR outcomes. The commercial leverage of improved landing-point selection is substantial: a 20% EUR improvement across a 40-well program is typically worth $100M+ in discounted NPV.