Oil prices have climbed towards $52 on worries about supply problems in the Gulf of Mexico and low oil inventories.
The price of light sweet crude rose 39 cents to $51.48 a barrel in New York, the highest in its 21-year history.
In London, Brent North Sea crude oil gained 42 cents to $47.55 a barrel, also a new all-time summit.
"There is a grim realisation that there is a chronic shortage of light sweet crude in the world," analysts said.
"Real panic is setting in, and the hurricane-related bad weather is still causing a backlog in US imports, so this afternoon's results will be interesting to say the least," they added.
Almost 27% of Mexico's 1.7 million barrels of daily production is still disrupted, according to the US Department of the Interior.
More than 15 million barrels, 2.5% of Mexico's annual oil production, have been affected.