Classification of Oil Reserves and Resources in the Former Soviet Union

Abstract

The terminology and principles of classification of oil reserves and resources that are presently used in Russia and other countries of the former Soviet Union (FSU) differ from those in the Western countries. This difference stems from the specificity of the Soviet practice in exploration, assessment, and keeping a record of resources that were controlled by the centralized government. In the FSU, the fundamental approach to the assessment of hydrocarbon resources is traditionally based on the extent to which the resources are explored. Such important factors as thickness of separate reservoir beds, their quality, physical characteristics of oil, the recovery factor, and the economic efficiency are not considered. Owing to this approach, the resource base appeared to be strongly exaggerated due to inclusion of reserves and resources that are neither reliable nor technologically and economically viable. A critical analysis of the long-term dynamics of reserves in the leading oil-producing regions of Russia, including west Siberia, shows a negative effect of the obsolete classification and errors in resource assessment on the development and production of oil fields. The classification of hydrocarbon resources presently used in Russia should be changed so that the principles of the new classification would be similar tomore » those commonly accepted in the oil business. A proposed new classification scheme will make the assessment of resource base for oil production in Russia more reliable. This scheme uses the principles of differentiation and assessment of hydrocarbon resources that are conventional in the world. Because no method of resource assessment is precise, the results of assessment should be presented in a probabilistic form or, at least, as an interval, but not as a single number assessment that is a common practice at present.« less