Sensitivity of Oil and Gas Reserves Sources of Estimation

New Russian classification of geological oil and gas reserves on categories and groups is schematized. The source of data about reserves - the geological and geophysical information - by origin, character, time of reception and a usage level is classified. The example of an estimation of reserves`sensitivity to a conditional deposit is brought, drawn a conclusion on the maximal dependence of reserves on deposit volume parameter and the minimal dependence on oil density and recalculation factor parameters.