Crude inventories rose by 2.6 million barrels in the week to Oct. 21 to 439.9 million barrels, nearly triple h analysts' forecasts in a Reuters poll for a 1 million-barrel rise.

Crude exports surged to a weekly record of 5.1 million barrels per day, cutting net crude imports to just over 1 million bpd, also a record. The United States has ramped up exports sharply in recent years since the Obama administration ended a 40-year ban in 2015.

"That export number is huge. It's the all-time record but that's no surprise" because of the big discount for U.S. crude to international benchmark Brent, said Robert Yawger, director of energy futures at Mizuho in New York. Coming into Wednesday's trade, the discount on U.S. crude was more than $8 per barrel to Brent.

Refinery crude runs fell by 114,000 bpd last week, EIA said, dropping refinery utilization rates by 0.6 percentage point to 88.9%.

That figure is still seasonally strong, however, as refining facilities run at higher-than-usual levels to meet expected increase in heating oil demand and as overall U.S. capacity has dropped in the last two years. East Coast refiners were running at 102.5% of their stated capacity due to low inventories in the region ahead of the winter months.

"East Coast refiners are moving heaven and earth to produce fuels, especially diesel," said John Kilduff, partner at Again Capital in New York.

Valero, the second-largest U.S. crude refiner, says it plans on operating its seven U.S. Gulf Coast refineries at about 95% of capacity through the fourth quarter due to tight supply.

Demand was marginally lower this week overall, but gasoline, jet fuel and distillate demand all rose. Over the past four weeks, U.S. refiners are supplying 20.4 million bpd in supply, down 2% from the year-ago period.

U.S. gasoline stocks fell by 1.5 million barrels in the week to 207.9 million barrels, while distillate stockpiles, which include diesel and heating oil, rose by 170,000 barrels.