Oil prices fell to their lowest levels in a year and a half this week and are down more than 20 percent for the year, depressed by rising supply and concerns about the health of the global economy.
U.S. crude inventories were down by 46,000 barrels in the week to Dec. 21, the Energy Information Administration said on Friday. Gasoline stocks rose by 3 million barrels, compared with analysts' expectations in a Reuters poll for a gain of 28,000 barrels.
"The report was modestly bearish, as crude oil stocks held steady versus expectations of a sizeable decline," said John Kilduff, a partner at Again Capital Management in New York. "The net effect of the report should keep prices fairly flat ahead of the weekend."
Traders appeared to be squaring their books ahead of expected light volumes on Monday and a market closure on Tuesday for the New Year's Day holiday.
"Looks like some people in the U.S. and UK got a nice opportunity to bail out of longs," Sukrit Vijayakar, principal and trader at Trifecta Consultants in Mumbai, told Reuters Global Oil Forum.
Stephen Innes, head of trading for Asia-Pacific at futures brokerage Oanda in Singapore, said crude prices had been pressured by slowing economic growth "coupled with the expectation of strong U.S. production in the new year."