Crude prices swung back and forth in choppy trade on Friday as traders closed positions at the end of a week that saw prices briefly rising by the most in over six years earlier in the session.
Market participants flipflopped between the negative fundamentals of persistent oversupply and support factors from Syria-related concerns and a weaker U.S. dollar.
"Prices are moving on profit-taking before the weekend. There is also a partial holiday in the U.S. on Monday," Commerzbank analyst Carsten Fritsch said, referring to the U.S. Columbus Day holiday.
Earlier in the session, Brent was on track to notch its highest weekly percentage gain since 2009, but some traders said the sharp rise was overblown, prompting speculators to take profits.
Brent, the global benchmark, was down 45 cents at $52.60 a barrel, during a volatile session that saw the contract touch an intraday high of $54.05.
U.S. crude settled up 20 cents, at $49.63 a barrel — rising more than 8 percent for the week.