U.S. oil futures fell on Friday and was on track for a fifth straight week of declines, while Brent remained under pressure on a strong dollar and plentiful supplies.
Traders and analysts said higher inventory at Cushing, Oklahoma, pushed the markets lower Friday after stocks in the delivery point for the U.S. oil contract fell to six-year lows earlier this month.
Last week, crude stocks at the Cushing delivery hub rose by 1.8 million barrels to 20.2 million barrels, the first time stocks there topped 20 million in a month, data from the Energy Information Administration showed on Wednesday.
The oil market appeared to rally for a short period before falling back, after Federal Reserve Chair Janet Yellen said the Fed needed to exercise caution when considering a rise in interest rates. Her remarks were made at the Kansas City Federal Reserve Bank's Jackson Hole, Wyoming conference.
Today's more modest declines come on the heels of hefty sell-offs earlier this week that drove Brent down to its lowest level since June 2013. An increase in production may also be calming fears overseas. In Libya, oil production continued to increase after the reopening of several eastern ports. Officials have also loaded a second tanker at Es Sider, Libya's largest oil export terminal, after it was shut for a year.
Exports from Iraq remain near record volumes despite an insurgency by Islamic State militants in the north. Crude is also being exported from Iraqi Kurdistan via Turkey in defiance of Baghdad.