As at 31 December 2011, the total "proven" and "probable" (2P) reserves of Gazprom Neft group under PRMS international standards amounted to 11.577 billion barrels of oil and 15.720 trillion cubic feet of gas, which translates into 14.197 billion barrels of oil equivalent.
Compared with the end of 2010, Gazprom Neft's hydrocarbon reserves increased by 8.78% (1.145 billion barrels of oil equivalent). Considering its production volume for 2011, the replacement level of Gazprom Neft's category 2P hydrocarbon reserves was 379% (1.567 billion barrels).
The reserves of Gazprom Neft and its joint ventures were audited by DeGolyer and MacNaughton.
Gazprom Neft group's total reserves include the company's stake in the reserves of dependent companies, recorded on the basis of the equity accounting method – the enterprises Slavneft, Tomskneft, Salym Petroleum Development, SeverEnergia and Messoyakhaneftegaz.
For over 10 years Gazprom Neft's reserves have been audited according to the PRMS (Petroleum Resources Management System) standards of the Society of Petroleum Engineers.