The worldwide economic downturn has hit energy consumption, but an expected recovery next year could respark demand and boost prices, the Energy Information Administration said in its new forecast.
S. oil prices are forecast to rise from an average $61 barrel this year to $110 in 2015 and $130 in 2030.
Oil prices "begin to rise in 2010-2011 period as the economy rebounds and global demand once again grows more rapidly than non-OPEC liquid supply," EIA acting administrator Howard Gruenspecht told a news conference.
Global oil demand is expected to rise to 107 million barrels per day over the next two decades from nearly 84 million bpd this year. Oil will account for 32 percent of the world's energy supply by 2030 from about 36 percent in 2006.
Almost 75 percent of the rise in global energy demand through 2030 will occur in developing countries, particularly China, India, Russia and Brazil, the agency said.
The Organization of Petroleum Exporting Countries will continue to provide 40 percent of the world's oil supplies during the period.
Renewable energy, like wind and solar power, will be the fastest growing energy source, making up 11 percent of global supplies. Biofuels, including ethanol and biodiesel, are expected to reach 5.9 million bpd by 2030.
The EIA said its long-term forecast does not reflect efforts the United States may take to cut greenhouse gas emissions or an expected international agreement to curb greenhouse gases.
Gruenspecht said the agency will analyze the possible impact of climate change legislation approved by the U.S. House of Representatives Energy and Commerce Committee.
But he said the bill may not change energy use initially, citing carbon dioxide emission limits and the allowed transfer of carbon cuts to developing countries.
"One could imagine that one could comply at least with the 2020 part of this proposal calling for a 17 percent reduction (from 2005 levels) just using the offsets and not having a significant change in our consumption or the way we use energy at all," Gruenspecht said.
If global climate change laws and policies don't change, world energy-related carbon dioxide emissions will rise by a third to 40 billion metric tons a year, the agency said.
The EIA's report also found that global natural gas demand will increase by almost 50 percent to 153 trillion cubic feet. The agency said that unconventional natural gas production, particularly from gas shale, will make the United States "virtually self sufficient in natural gas supply in 2030."
The EIA's forecast also predicts that in 2030:
World production of unconventional petroleum resources, including oil sands, extra-heavy oil and coal-to-liquids, will quadruple to 13.4 million bpd, representing 13 percent of total global petroleum supplies.
Iraq's crude oil production will jump from 2 million bpd to 5 million bpd.
China's electricity generation from coal-fired power plants will triple.