Oil prices dipped for a second day in a row on Friday as some investors took profit on a surge to seven-month highs while others worried about higher production with the market hovering near $50 a barrel.
A stronger dollar also weighed on demand for dollar-denominated oil from holders of other currencies. The dollar spiked after Federal Reserve Chair Janet Yellen said a U.S. rate hike was probably appropriate in coming months.
A three-day weekend for the United States, owing to Monday's Memorial Day holiday, further discouraged investors from holding bullish bets. Also on Friday, oilfield services firm Baker Hughes reported the number of rigs operating in U.S. fields fell by 2 to 316 in the previous week. At this time last year, drillers had 646 oil rigs online.