BP Annual Report and Form 20-F 2011 - Company Reporting

Supplementary information on oil and natural gas (unaudited)Movements in estimated net proved reserves continuedmillion barrelsBitumen a 2011Rest ofNorthAmericaTotalEquity-accounted entities (BP share)At 1 January 2011Developed – –Undeveloped 179 179179 179Changes attributable toRevisions of previous estimates (1) (1)Improved recovery – –Purchases of reserves-in-place – –Discoveries and extensions – –Production – –Sales of reserves-in-place – –(1) (1)At 31 December 2011Developed – –Undeveloped 178 178178 178aProved reserves exclude royalties due to others, whether payable in cash or in kind, where the royalty owner has a direct interest in the underlying production and the option and ability to make lifting andsales arrangements independently.268 BP Annual Report and Form 20-F 2011