New York's West Texas Intermediate rebounded strongly yesterday settling at $US138.91, after reaching a peak of $US140.39 in overnight trade.
Singapore's Tapis, however, remained steady this week, closing lower at $139.88 last night.
The latest surge in oil prices came as the US dollar weakened against the Euro, a day after the US Federal Reserve decided to leave interest rates unchanged.
Crude also rose after OPEC president Chakib Khelil said the commodity could hit $US170 a barrel this year because of the ailing US dollar and geopolitical unrest.
"I predict probably prices of $US150 to $US170 this (northern) summer," Khelil said in an interview with the France 24 news channel.
Rhetoric from Libya, a member of the Organisation of Petroleum Exporting Countries, also added to the rise, sparking new supply fears.
The chief of Libya's national oil company Shokri Ghanem repeated his Sunday comments that Libya "sees a possibility for a decrease in production," according to Bloomberg News.
Libya produces about 1.8 million barrels a day and considers that the oil market is saturated.
On Wednesday prices tumbled more than $US3 after an unexpected rise in US crude stockpiles and reassurance by oil giant Shell that the situation in Nigeria is under control.
The US Department of Energy's weekly report on energy reserves found crude stockpiles climbed by 800,000 barrels to 301.8 million barrels.
Prices were also driven down by Shell's reassurance about its situation in Nigeria.
Shell said it had resumed operations at the Bonga offshore oil field after an attack by militants last week cut production by 200,000 barrels a days.
On Tuesday, OPEC president Chakib Khelil snubbed calls from oil-consuming nations for increased output from the cartel, pushing prices towards $138 a barrel.
"OPEC had already done what OPEC can do and prices will not come down," Khelil said as he arrived for a meeting with European Energy officials in Brussels.
The cartel, which pumps about 40% of the world's crude oil, insists there is enough oil to meet demand.
Khelil blamed the high prices on the US subprime crisis, the impact of the dollar and the influx of funds that were looking for good returns they could not find in other investments.
