Oil regained some ground on Thursday following upbeat data from an industry group that USA crude inventories fell sharply last week.
The Financial Times on Friday reported that Igor Sechin, chief of Russia's largest oil producer Rosneft, said U.S. oil companies could add up to 1.5m b/d to global output next year, countering production curbs by Opec and producers outside of the cartel.
Crude oil prices continued to trend higher for the second consecutive fortnight in a row.
On Thursday OPEC Secretary-General Mohammad Barkindo said to an economic forum in Russian Federation that it was too early to say when production caps could be imposed on Libya and Nigeria as they have a lot of issues to solve.
On oil price decline, he said, "We have no issues with people taking positions in the market; we are focusing on fundamentals".
In Libya, the state oil firm said output had reached 827,000 bpd on Wednesday, around levels last seen in 2014.
U.S. President Donald Trump's withdrawal from the Paris agreement, the landmark 2015 global pact to fight climate change, drew condemnation from Washington's allies and many in the energy industry - and sparked fears that U.S. oil production could expand more rapidly than it is now.
The general trend among US producers points to a need to boost growth forecasts amid anticipated production acceleration the second half of this year, said consultancy Energy Aspects.
Data released Thursday by the U.S. Energy Information Administration showed that commercial crude inventories fell by 6.4 million barrels in the week to May 26, compared with analyst expectations for a decrease of 2.5 million barrels.
With Crude Oil down 3.5% below $48 a barrel and Brent Oil 3.43% at just over $50 a barrel, Wednesday was not a good day to be a petro-currency, as the Canadian Dollar and particularly the Norwegian Krone fell across the board in sympathy with their major export.
US crude production rose almost 500,000 barrels per day (bpd) last week from year-earlier levels.
Crude oil prices have been dampened by rising USA output despite Opec production cuts.
OPEC crude output rose in May driven by gains from Libya and Nigeria who are excused from the agreement to cut production in an effort to recover oil prices.
Traders are also likely to respond to this week's Baker Hughes rig count report that could show an increase for the 20 consecutive week. But production is still half the 1.60 million bpd Libya pumped before the 2011 civil war.
Faced with a lingering glut, OPEC last week discussed reducing output by a further 1 to 1.5 percent, and could revisit the proposal should inventories remain high, sources told Reuters.
USA producers aren't part of the output agreement.
"This is a little bit of a bounce back from last Thursday when we had a really heavy drop", an energy economist at the Arkansas-based WTRG Economics James Williams, said before adding that at current production levels OPEC will not be able to balance supply in nine months.