Possible reserves

Unproved reserves are based on geologic and/or engineering data similar to that used in estimates of proved reserves but technical, contractual, economic, or rcgulatoiy uncertainties preclude such reseiwes being classified as proved. Unproved reserves may be further divided into two subcategories probable reserves and possible reserves. 

Possible rcsciwcs arc those unproved rcsci vcs which analysis of geological and engineering data suggests are less likely to be recoverable than probable reseiwes. In this context, when probabilistic methods are used, there should be at least a 10 percent probability that the quantities actually recovered will equal or exceed the sum of estimated proved plus probable plus possible reserves. 

Proven, Probable, and Possible Reserves and Associated Probabilities... 

In the SPE/WPC scheme, reserves are classified according to the probability with which they can be produced into proved , probable and possible reserves. Under these definitions, proved reserves are those with a probability of at least 90% (P90) that the estimated volumes can be produced profitably proved plus probable reserves are required to have at least 50% probability (P50), while proved plus probable plus possible reserves are based on a probability of at least 10% (P10). 

Probable reserves are those reserves of petroleum that are nearly certain but about which a slight doubt exists. Possible reserves are those reserves of petroleum with an even greater degree of uncertainty about recovery but about which there is some information. An additional term potential reserves is also used on occasion these reserves are based upon geological information about... 

Possible reserves reserves where there is an even greater degree of uncertainty but about which there is some information. 

Potential Reserves (Probable Reserves, Possible Reserves)... 

These reserves are the additional reserves of coal that are believed to exist in the earth. The data are estimated (usually from geological evidence) but have not been substantiated by any drilling or coring operations. Other terminologies such as probable reserves and possible reserves are also employed but fall into the subcategory of being unproven. 

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