Trade disputes and a stronger dollar have weakened demand of Asia's biggest buyers
Crude prices fall amid concerns over global growth
Oil prices fell on Friday, with US crude heading for a seventh weekly decline amid increasing concerns about slowing global economic growth that could hit demand for petroleum products as inventories build.
Brent crude oil futures were down 3 cents at $71.40 a barrel by 00229 GMT. US West Texas Intermediate (WTI) crude futures dropped 1 cent to $65.45 a barrel.
Brent is heading for a 2 per cent decline this week, a third consecutive weekly drop. WTI is on track for the seventh week of losses, with a fall of more than 3 per cent.
Data on Wednesday showing a large build in US inventories fostered fears about the outlook for fuel demand, while crude was also pressured by broader selling of industrial commodities and by the Turkish financial crisis.
"Investors remain cautious as Wednesday's surprise gain in US stockpiles remained fresh in their minds," ANZ said in a note.
China and the United States have implemented several rounds of trade tariffs and threatened further duties on exports worth hundreds of billions of dollars, which could knock global economic growth.
At the same time, the crisis gripping the Turkish lira has rattled emerging markets and reverberated across equities, bonds and raw materials.
US data on Wednesday showed crude output rose by 100,000 barrels per day to 10.9 million bpd in the week ending August 10.
Crude inventories increased by 6.8 million barrels, representing the largest weekly rise since March last year.
Asian demand is showing signs of slowdown as trade disputes and a stronger dollar drag the economies of some of the world's largest oil buyers.