Oil dropped to $66 a barrel on Friday, under pressure from concerns that rising U.S. oil output and exports will offset OPEC-led attempts to erode stockpiles with output curbs.
U.S. oil production last week was steady at 10.27 million barrels per day, a record level if confirmed by monthly figures. Crude exports jumped to more than 2 million bpd, close to a record 2.1 million hit in October.
Brent crude, the global benchmark, was down 45 cents at $65.94 at 1052 GMT. Prices had rallied in early 2018 and reached $71.28 on Jan. 25, the highest since December 2014. U.S. crude fell 34 cents to $62.43.
Oil also slipped as the U.S. dollar strengthened. A stronger dollar can make oil and other commodities denominated in the U.S. currency more expensive for other currency holders.
The latest decline for crude came despite the U.S. Energy Information Administration reporting crude stocks fell unexpectedly by 1.6 million barrels. Analysts said low import figures contributed to the decline.
U.S. production is expected to rise even more this year and top 11 million bpd in late 2018, a headwind for OPEC efforts to drain stockpiles.
However, the Organization of the Petroleum Exporting Countries is not outwardly worried by rising U.S. output and says it is comfortable at the speed the market is moving toward balance.
In January 2017, OPEC and allies including Russia began to cut production by about 1.8 million bpd, almost 2 percent of global supply, to get rid of a glut that had built up since 2014 and that led to a price collapse.
OPEC wants to reduce oil inventories held by industrialized nations to their five-year average and is getting closer to that goal, although officials are starting to talk about looking at different metrics.