Oil prices were down more than 3 percent on Wednesday after the U.S. government reported a crude build three times above analysts expectations.
The increase marked the sixth straight week of record high inventories, rekindling worries of a glut that threatened to reverse a two-month long rally on the market.
The Energy Information Administration reported U.S. crude stocks rose by 9.4 million barrels in the previous week to a record total of 532.5 million barrels.
The U.S. Energy Information Administration (EIA) said crude stockpiles rose 9.4 million barrels last week, not far from the 8.8 million build indicated by industry group American Petroleum Institute on Tuesday but way off the 3.1 million barrels expected by analysts in a Reuters poll.
"The data will do little to help oil bulls, given the monster build for crude inventories already at record high levels prior to this," said Chris Jarvis, analyst at Caprock Risk Management in Frederick, Maryland.