DEFINITION of 'Possible Reserves'
An estimate of the amount of oil or natural gas reserves that may be available for extraction. Reserve figures are broken into two primary categories according to theoretical accuracy: proved and unproved. Unproved reserves carry more uncertainty, and are further broken into "probable reserves" and "possible reserves", the latter of which has a lower probability of being recovered.
BREAKING DOWN 'Possible Reserves'
Because of the geological complexity surrounding natural resource exploration, oil reserve figures are more of an approximation than an exact estimate. Estimates are typically revised as more information on the geological makeup of a particular reserve is uncovered. In addition, technological advances may increase the amount of oil or gas that can be recovered, as less of the natural resource will go to waste as efficiency increases.