The volume of Slavneft’s audited proven reserves of oil and gas, as calculated under the United States SEC rules without accounting for the active period of licenses, was 2.267 millions barrels as of 31 December 2009, Slavneft reported. This figure is up 64 million barrels, or 3 percent, on 2008. The company's ratio of growth in recoverable crude resources (202 million barrels) to 2009 production volume (138 million barrels) reaches 146 percent under SEC rules.
This growth under SEC criteria is due to the high effectiveness of the company’s geological exploration work which uses modern drilling methods as well as geological and technical work to increase output. According to the auditor’s conclusions, Slavneft’s proven reserves of oil equivalent based on SPE measurements totaled 2.906 billion barrels as of 1 January 2010, up 237 million barrels or 9 percent on 2008.
The audit on Slavneft hydrocarbon reserves was conducted by the US consulting firm Miller&Lents, which has been the company’s auditor since 1997. In 2009, 37 fields in West Siberia and East Siberia were audited under SPE and SEC rules.