Category:Reserves
From Eurêka
Reserves Proportion of a resource, especially minerals, which can be exploited under existing economic conditions and with available technology. Reserves are developed from resources through the application of technology, capital and expertise in response to cost and price changes. Various reserve categories have been established.
Recoverable reserves Amount of mineral likely to be extracted for commercial use within a certain time-span and level of technology.
Speculative reserves Deposits that may exist in geologic basins or terrain where no exploration has yet taken place but the geologic makeup of the earth’s crust is similar to that of regions that have yielded minerals.
Proven reserves (Commercial reserves) Deposits of fossil fuels already discovered and known to be economically extractable. Essentially, what it has so far been in the commercial interest of an industry to discover. The amount and recoverability of the mineral has been measured within small margins of geological, geophysical and engineering error (less than 20%), e.g. by properly spaced drill-holes. Such reserves are virtually certain to be technically and economically producible and there is a 90% chance that the actual quantity extracted is greater than the amount estimated.
- Measured reserves Same as proven reserves but for metallic ores.
Identified mineral resources Specific mineral deposits of known quality and quantity.
Conditional reserves Deposits which have already been discovered, but they are not economic to work at present-day price levels with currently available extraction and production technologies.
Operating reserves Expression used in coal-mining to describe reserves available in mines currently producing coal.
Probable reserves (fossil fuels) Reserves that involve a greater element of risk, since their existence and quantity are estimated, on the basis of geologic information and judgment, partly from sample analysis and partly from reasonable geologic projections outwards from exploratory drill-holes into or through one or more producing horizons. They are estimated to have a better than 50% chance of being economically and technically producible and there is a 50% chance that quantities recoverable will be greater than estimated.
- Indicated reserves Probable reserves of metallic ores.
Possible reserves (fossil fuels) Deposits in unexplored extensions of established areas of production, i.e. outside present production fields or mines but within formations proved to be productive. These are estimated by geologic projection and involve substantial risk, estimated to have a significant but less than 50% chance of being economically and technically producible.
- Inferred reserves Possible reserves of metallic ores.
Potential reserves Regarded by the oil industry as including probable, possible, and speculative reserves but by metal mining as including only indicated and inferred reserves.
Reserves-production ratio (R/P ratio) Ratio between the annual production rate of a mineral and the proven or measured reserves remaining in the ground. It therefore indicates the number of years of production remaining at the current annual rate of production, assuming no other deposits are discovered. The R/P ratio may be calculated for an individual mine or field but is more commonly calculated at regional, national and global scales.
Mckelvey box Classification system of mineral resources based on a matrix with columns defined by increasing degree of geological certainty as to chemical composition, concentration, orientation and extent of certain deposits as well as constraints on access to them. Rows are defined in terms of profitability, with reference to markets, production costs and the availability of feasible processing techniques.
