Oil prices closed slightly higher Friday, crawling out of deep session losses in a market gripped by worries about weakening global demand and a supply glut.
The volatility came as traders positioned ahead of the weekend after a week marked by sell-offs and rising worries about slowing global economic growth, especially in the eurozone.
US benchmark West Texas Intermediate for November delivery edged up five cents to close at $85.82 a barrel on the New York Mercantile Exchange.
Brent North Sea crude for delivery in November recovered from a four-year low to score a gain of 16 cents, settling at $90.21 a barrel in London.
In earlier Asian trade, WTI sank to $83.59, its lowest level since July 3, 2012, and Brent had tumbled to $88.11, touching the lowest level since December 1, 2010.
"Volatility skew went ballistic," said BMO Capital Markets.
The stabilization in prices by the end of trade was a sign of "people trying just to get flat for the weekend. Nobody really knows what is going to happen," said Carl Larry of Oil Outlooks and Opinions.
"Fears of a slower global economy are not just impacting the crude complex, spreading to broader markets to now manifest itself in a full-on flight from risk across the board," said Matt Smith of Schneider Electric.
The oil market action came as equities markets on both sides of the Atlantic were hit by selling amid growing signs that the eurozone is at risk of recession and the global economy is slowing, and worries about the Ebola epidemic in West Africa.
"The price slide has doubtless become more speculative in nature of late as the deteriorating global economic outlook, growing risk aversion and ample supply prompt more and more market players to bet on falling prices," said Commerzbank in a research note.