It's hard to shed a tear for Big Oil. The top five publicly traded companies racked up a record $119.5 billion profit last year – roughly the size of Ireland's economy.
Yet these corporations are steadily losing ground to a surging group of nationally run companies – a trend that could come back to hurt oil-consuming nations such as the United States, some experts say.
The risk is that governments that run oil companies will lavish so much of their oil wealth on social programs and other priorities that efficiency and investment in new oil fields will suffer.
"We could have a problem down the road because not enough investment will be made," says Amy Myers Jaffe, an energy expert at Rice University's Baker Institute for Public Policy in Houston. In Venezuela, Iran, and Russia "we might see declines in production in coming years." These countries have huge reserves and state-run energy sectors with questionable efficiency.
Many forecasters expect that world oil output will continue to rise, along with demand, in the years ahead. But in this era of newly resurgent national oil companies – the NOCs, in industry jargon – any forecasts have a large margin for error.
• Iran, now among the world's leading crude-oil exporters, could become a net importer of oil within the next decade. The reasons include both rising demand, driven in part by huge government subsidies for gasoline, and slow-growing production.
• Venezuela is moving toward tighter national control of its industry, with President Hugo Chavez saying he wants to share oil wealth with the country's often- impoverished citizens. But the more that is spent on social programs, the less remains for investment. Last year, when Exxon-Mobil was reporting record profits, Venezuela's PDVSA posted a 26 percent decline in profits, the company reported.
• In Russia, the government of Vladimir Putin has stirred up controversy with its own brand of "resource nationalism." Analysts say the government pressured Royal Dutch Shell to hand over control of one major project, on Sakhalin Island, to Russia's Gazprom in December. As in Venezuela, such moves could strain the confidence of international oil companies in forming partnerships with Russia.