The U.S. Energy Information Administration said in its weekly report that crude oil inventories rose by 6.2 million barrels in the week ended April 27.
That compared with analysts' expectations for an increase of 789,000 barrels, while the American Petroleum Institute late Tuesday reported a supply-gain of 3.4 million barrels.
Supplies at Cushing, Oklahoma, the key delivery point for Nymex crude, rose by 416,000 barrels last week, the EIA said.
Total U.S. crude oil inventories stood at 436.0 million barrels as of last week, which the EIA considered to be in the lower half of the average range for this time of year.
Domestic oil production- driven by shale extraction - rose to a fresh all-time high of 10.61 million barrels per day last week. Only Russia currently produces more, at around 11 million bpd.
The report also showed that gasoline inventories increased by 1.2 million barrels, compared to expectations for a decline of 587,000 barrels.
For distillate inventories including diesel, the EIA reported a drop of 3.9 million barrels.
Oil Inventory Report - May 2
Oil Inventory Report - May 2
Dan Steffens
Energy Prospectus Group
Energy Prospectus Group