Stout demand growth has whittled spare global oil capacity to its lowest point in 30 years, mostly due to China's thirst for fuel.
But despite crude prices that flirted with $50 a barrel last month, non-OPEC nations now pump as much as 8 billion barrels of oil more than they discover annually, Washington-based energy consultant PFC Energy said.
There is no imminent danger of exhausting world oil supplies, PFC said. But reserve depletion could cut into supplies if countries cannot find ways to replace production from tapped out fields, PFC warned.
Notable discoveries in African nations like Nigeria, Angola, and Equatorial Guinea are unlikely to stem the decline, PFC said.
"We're producing more than we find by a considerable amount," Mike Rodgers, a senior director at PFC, said at a presentation for the Center for Strategic and International Studies. "We don't really see this changing very much between now and the end of the decade."
Non-OPEC nations brought major projects on-line in the 1980s, which are starting to either peak out or decline, PFC said.
Countries like Mexico, Malaysia,, and China have hit production plateaus that will be hard to maintain, it said.
The notable exceptions are OPEC nations and former Soviet states, which will be the world's swing suppliers in coming years along with West African nations, PFC said.
And OPEC, which has long sat on spare capacity, could find itself unable to keep pace with demand by 2020 assuming global demand growth of 1.8 percent a year, PFC said.
OPEC cartel members produce about 8 billion barrels per year more than they discover, PFC said.
"There are reasons to worry about OPEC's ability to fill that growing differential between non-OPEC production and global demand under current growth scenarios," Rodgers said.
Saudi Arabia, the only OPEC nation with any real spare capacity, is unlikely to see production above 14 million barrels, PFC said. The kingdom in August produced 9.5 million bpd versus its capacity of 10 million bpd, according to U.S. government data.
Former Soviet nations like Kazakhstan and Azerbaijan are counting on a raft of new pipelines to bring their oil to market. Total FSU production could rise by 2 million bpd to peak at 14 million bpd by 2010, PFC said.
These factors will make the United States increasingly dependent on Latin American and West African crude, PFC said.
In the past the Middle East has been the swing supplier for the United States. But as Europe and Asia draw more OPEC oil, West African nations like Angola will supply more U.S. oil, PFC said.