Crude prices edged higher on Friday, but were heading for yet another weekly decline on worries that oversupply would weigh on the U.S. market and that trade disputes and slowing global economic growth would slow demand for oil.
U.S. crude was on track for its seventh consecutive weekly decline and global benchmark Brent was set to drop for a third week, Reuters said.
"One of the biggest concerns out there is that China's demand numbers are coming down if China's GDP growth is slowing," said Tariq Zahir, managing member at Tyche Capital in New York.
Brent crude oil futures LCOc1 were up 47 cents at $71.90 a barrel by 11:29 a.m. EDT (1529 GMT), after rising over $1 to hit a high of $72.44 a barrel.
U.S. West Texas Intermediate (WTI) crude futures CLc1 rose 49 cents to $65.95, after touching a session high of $66.39 earlier.
For the week, Brent was heading for a 1.3 percent loss, and U.S. crude was down 2.5 percent.
Friday's pull back from session highs came on mounting worries that U.S. crude inventories would post another consecutive gain, said Bob Yawger, director of futures at Mizuho Americas.
U.S. government data this week showed a large build up in crude inventories C-OUT-T-EIA, with production C-OUT-T-EIA also increasing.
"Investors remain cautious as Wednesday's surprise gain in U.S. stockpiles remained fresh in their minds," ANZ bank said on Friday.
A weekly report on U.S. drilling activity is due to be published at about 1 p.m. by energy services firm Baker Hughes. Last week, drillers added 10 oil rigs, the biggest rise since May.
Another major drag on prices was the darkening economic outlook on the back of trade tensions between the United States and China, and weakening emerging market currencies that are weighing on growth and fuel consumption, traders and analysts said.