First, reserves are the quantities of oil that are anticipated to be commercially recoverable. Unrecoverable quantities of oil are referred to as contingent resources and prospective Resources.

Proved reserves are the quantities of oil that can be estimated with reasonable certainty to be commercially recoverable.

Probable reserves are the additional reserves that are less likely to be recovered than proved reserves.

Possible reserves are the additional reserves that are less likely to be recoverable than probable reserves.