"The world's daily oil consumption is expected to climb to 121 million barrels in 2030, from about 82 million barrels in 2004, according to the International Energy Agency. Where will that oil come from?
Despite producing at a record level of 30 million barrels a day, OPEC now accounts for only a third of the world's oil production. But that market share is expected to increase significantly, reaching more than 50 percent in 2030, as countries like Saudi Arabia, Kuwait and Iran, which have ample reserves, increase their investments and raise production.
But for many other producing countries, from Norway to Mexico, the picture is quite different. New discoveries are too few and too small to offset declining output at mature and aging fields. In the North Sea, for example, production is expected to fall almost by half, to three million barrels a day, in 2020.
Russia, which has been highly successful at increasing its production from its post-Soviet low of six million barrels a day, is expected to reach a plateau of about 11 million barrels by the end of the decade."
EDIT
http://www.nytimes.com/2005/01/03/business/03oiloutput.html?oref=login&pagewanted=all