Definitions for

**"Probable Reserves"****Related Terms:**Possible reserves, Proven reserves, Established reserves, Proved reserves, Prior probability, Posterior probability, Reserves, Ore reserves, Reserve, P-value, Uncertainty, Mineral reserve, Mineral reserves, Likelihood, Bayes' theorem, Statistical significance, Statistically significant, Significance, P value, Uncertainty, Level of significance, Critical value, Chi-square, Significant, Significance test, Ore reserve, Expected value, Probability, Extrapolation, Confidence level, Significance level, Likelihood function, Projection, Theoretical probability, Likelihood ratio, Indicators, Conditional probability, Test statistic, Probability distribution, Probability theory, Power, Expectation, Proved undeveloped reserves, Sensitivity analysis, Forecasting, Hypothesis test, Alpha, Forecast, Negative predictive value

Reserves with a higher degree of risk associated with its ultimate realization

Probable reserves are less certain than proved reserves and can be estimated with a degree of certainty sufficient to indicate they are more likely to be recovered than not. Note that probable reserves have not been risked.

Areas which are unproven but presumed capable of production because of geological inference, for instance, proximity to proven reserves in the same reservoir.

The economically mineable material derived from a Measured and/or Indicated Diamond Resource. It is estimated with a lower level of confidence than a Proved Reserve. It is inclusive of diluting materials and allows for losses that may occur when the material is mined. Appropriate assessments, which may include feasibility studies, have been carried out, including consideration of, and modification by, realistically assumed mining, metallurgical, economic, marketing, legal, environmental, social and governmental factors. These assessments demonstrate at the time of reporting that extraction is reasonably justified.

Reserves that are believed to be economically producible but whose estimates have an equal probability that the ultimate realized recoveries will be higher or lower than the published figure; probable reserves generally require additional capital to be brought on-production, including development wells, gathering systems and possibly other surface facilities.

An estimate of oil and/or gas reserves based on penetrated structures, but needing more advanced confirmation to be classified as proven reserves.

in respect of quantities of oil and gas, probable reserves are those reserves which are not yet proven but which, on all the available evidence and taking into account technical and economic factors, have a better than 50 per cent chance of being produced

(see Reserves).

undeveloped oil and gas reserves from tested formations, but for which there is a lack of information.

Reserves believed to exist with reasonable certainty based on geological information.

Those reserves which are not yet proven but have a better than 50% chance of being produced, based on technical and economic factors.

Those reserves that analysis of drilling, geological, geophysical and engineering data does not demonstrate to be proved, but where such analysis suggests the likelihood of their existence and future recovery under current technology and existing economic conditions. Probable reserves to be obtained by the application of enhanced recovery processes will be the increased recovery over and above that estimated in the proved category, which can be realistically estimated for the pool on the basis of enhanced recovery processes that can be reasonably expected to be instituted in the future.

Those reserves which are not yet proven but which are estimated to have a better than 50% chance of being technically and economically producible.

Resources for which tonnage and grade and/or quality are computed primarily from information similar to that used for proven reserves, but the sites for inspection, sampling and measurement are farther apart or are otherwise less adequately spaced. The degree of assurance, although lower than that for proven reserves, is high enough to assume continuity between points of observation.

Additional reserves that are less certain to be recovered than proved reserves. It is equally likely that the actual remaining quantities recovered will be greater or less than the sum of the estimated proved plus probable reserves. There must be at least a 50% probability that the quantities actually recovered will equal or exceed the sum of the estimated proved plus probable reserves.

Those reserves which analysis of drilling, geological, geophysical and engineering data does not demonstrate to be proved under current technology and existing economic conditions, but where such analysis suggests the likelihood of their existence and future recovery. Probable reserves to be obtaiend by the application of enhanced recovery processes are the increased recovery over and above that estimated in the proved category which can be realistically estimated for the pool on the basis of enhanced recovery processes which can be reasonaly expected to be instituted in the future

Valuable mineralization not sampled enough to accurately estimate the terms of tonnage and grade. Also called "indicated reserves."

Estimated oil and/or gas reserves in an area where preliminary tests have been performed and drilling has commenced, but needing more detailed analysis to be confirmed as a commercially viable source of oil and gas.

Production casing