1.) Reserves Categories

Deterministic Reservoir Classes:

• Probable – Likely (It’s probably there / it’s probably this big)

• Possible – Could be there / could be this big

• Proved – Best estimate / High confidence

Probabilistic Reservoir Classes:

• Proved – High confidence (P₉₀)

• Probable – Most Likely (P₅₀)

• Possible – High side volumes (P₁₀)

Reserves Categories:

• Behind Pipe

• Undeveloped

• Non-producing

• Producing

Common Examples Of Reservoir Class & Category:

• PDP (proved developed producing)

• PDNP (Proved developed non-producing)

• PBP (Proved behind pipe)

• PUD (Proved undeveloped)

Less Common Reservoir Examples:

• (PrNP) Probable non-producing

• (PrBP) Probable behind pipe

• (PsUD) Possible undeveloped

What’s the difference between Reserves and EUR (Estimated Ultimate Recovery)?

• EUR is the ultimate amount of oil & gas that will be produced over the life of a well.

• Reserves are volumes of oil and gas that are left to produce.

• You have to know “as of date”

What are some of the types of reserves?

• Condensate

• Associated gas

• Non associated gas

• NGLs (natural gas liquids)

• Crude oil

2.) Decline Curve Analysis

Creating Type Curves:

• Select wells based on appropriate criteria

• Review & cull the production data

• Don’t use any data after reaching 50% of the well count

Contact Us With Any Questions You May Have!