Oil prices eased on Tuesday as traders began to unwind positions in the run-up to the year-end holiday season.
U.S. West Texas Intermediate (WTI) crude oil futures were trading at $51.97 per barrel at 0134 GMT, down 15 cents from their last settlement.
International Brent crude oil futures were down 1 cent from their last close at $54.91 a barrel.
Traders said the slight dip was a result of market players squaring their books ahead of the upcoming Christmas weekend and the week running up to New Year, during which many offices will be shut.
Analysts said they expected markets would likely remain tepid this week, with no fundamentals expected that could drive large price swings.
"With little data due, prices are likely to drift aimlessly in today's session," ANZ bank said.
Jeffrey Halley, senior market analyst at OANDA brokerage in Singapore, said "a light news week and the run-in to the holiday season" was keeping markets quiet.