Crude prices slipped on Friday after the U.S oil rig count rose the first time since December, renewing worries of a supply glut after an output freeze plan helped boost the market to 2016 highs and multi-week gains.
U.S. energy firms this week added one oil rig after 12 weeks of cuts, according to data by industry firm Baker Hughes. The addition, coming after oil rigs had fallen by two-thirds over the past year to 2009 lows, showed crude drilling picking up again after a 50 percent price rally since February.
"The rig count and crude prices have a direct relationship for sure," said Pete Donovan, broker at Liquidity Energy in New York.
Brent crude was down 24 cents at $41.30 a barrel, having risen $1 earlier to a 2016 high of $42.54.
U.S. crude for April delivery settled at $39.44 a barrel, was down 76 cents, or 1.89 percent, after gaining $1 earlier to a year high of $41.20.