Oil prices climbed back to $50 today, pushed higher by supply outages in the North Sea and fears about low stocks of winter heating fuels.
US crude oil futures rose 54 cents to $50.30 a barrel and in London, benchmark Brent futures gained 90 cents to $46.65. Prices have risen by around 50 percent since January and are less than $6 off a record high hit in late October, buoyed by fears that winter fuel stocks are too low in major consuming nations.
"Winter will play a big part," said analyst Mr Kevin Norrish of Barclays Capital. "Let's face it, we have not yet reached the seasonal peak for winter demand."
The OECD said today that soaring oil prices dealt a blow to the global economy in recent months but the growth should rebound next year.
"Despite recent oil price turbulence the world economy will regain momentum in a not-too-distant future," OECD chief economist Mr Jean-Philippe Cotis said.
The world could and would have to learn to live with more expensive oil because of soaring demand from booming emerging market economies such as China, Mr Cotis said.
Oil at $40 would not inflict much damage on economic growth but a sustained run at $50 could do lasting harm, he said.
Limited spare production capacity in the face of strong global demand means unexpected supply outages, especially of high-quality North Sea crude, have bolstered prices.
More than 280,000 barrels per day (bpd) of North Sea oil production remained halted today after two separate gas leaks shut fields in the Norwegian and UK sectors.
Saudi Oil Minister Mr Ali al-Naimi said on Monday that while global stocks of petroleum products such as heating oil remained below par, inventories were rebuilding and crude output was running slightly ahead of demand.
The dollar's fall to record lows last week has also raised unease in OPEC nations as their petro-dollar revenues will be worth less in the eurozone and Asia.
OPEC's second largest producer Iran believes OPEC should crack down on excess output over self-imposed quotas when ministers meet in Cairo on Dec 10. Other OPEC members are generally reluctant to advocate an output cut but that could change as any stock build gathers momentum early next year, analysts said.
"The more stocks appear likely to build in the second quarter, the more likely we are to have another year of high prices. OPEC is probably getting concerned and overproduction could be trimmed," said Norrish of Barclays Capital.