U.S. Crude oil fell 2% on Tuesday on expectations of rising supplies and a rebound in refinery throughput ahead of summer driving season in the United States, the world's biggest market.
U.S. crude settled $1.31 lower at $64.40 a barrel . London Brent crude, fell 65 cents .
U.S. government oil inventory data due out on Wednesday is expected to show a 1 million barrel build in crude supplies last week, according to a Reuters survey of analysts.
The polls forecast a rise in refinery runs, which could help U.S. companies build up stocks ahead of the summer.
Rising U.S. gasoline futures have underpinned oil prices in recent weeks, as refinery maintenance and glitches have drawn down fuel inventories sharply since early February.
"One thing we are looking for is an improvement in runs," said Eric Wittenauer at A.G. Edwards.
Gasoline stocks were expected to fall by 1 million barrels, the forecast showed.
Oil rallied sharply on Friday after top exporter Saudi Arabia said it had arrested Islamic militants, including trainee pilots preparing for suicide operations against oil facilities.
Brent crude drew support in early activity from news that Chevron had shut down 15,000 barrels per day (bpd) of crude production in OPEC member Nigeria following the kidnapping of oil workers by armed militants.
One-fifth of oil production remains offline in Africa's biggest producer despite expectations that output would increase following elections.
"It underscores the uncertainty there. The widespread assumption was that the shut-in production would come back onstream after the election," said Mike Wittner of Calyon Corporate and Investment Bank.
"It's not the 15,000 bpd but the fact that there could be more to come."