Shell not sure of itself

ROYAL DUTCH/Shell slashed its proved reserves by 20% last month. The shock announcement caused a sharp fall in the company's share price, damaged investor confidence in its management and prompted a wider debate on how oil companies should account for their reserves. The biggest revisions were at Australia's Gorgon project and in Nigeria—combined, the two countries accounted for half of the total revision. In a press release, on 9 January, Shell said it will shift 3.9bn barrels of oil equivalent (boe) of proved reserves into the probable category—the largest such reclassification ever. Two-thirds of the total (2.7bn barrels) relates to crude oil and natural gas liquids and one third (1.2bn b