This excerpt taken from the PBR 6-K filed Jan 16, 2009.
According to ANP/SPE criteria:
On December 31st, 2008 Petrobras' Proved Reserves of oil, condensate and natural gas amounted to 15.85 billion de boe, a 0.5% increase compared to last year, distributed as shown:
According to the SPE criteria, 949 904 million boe were incorporated into Proved Reserves in 2008 and 829 million boe were produced, resulting in an increase of 75 million boe in relation to 2007 proved reserves (15.010 billion boe). Consequently, for each barrel of oil equivalent produced during 2008, 1.09 barrels were incorporated into Proved Reserves, resulting in a Reserve Replacement Index – RRI of 109%. The Reserves/Production ratio (R/P) was 18.2 years.