London Brent crude for November delivery was down 47 cents at $49.52 a barrel early on Friday after rising above $50 for the first time in two weeks and settling up $2.01, or 4.2%, on Thursday.

NYMEX crude for October delivery was down 40 cents at $47.22 after settling up $2.12, or 4.7%, on Thursday.

"Spread trade is accelerating profit-taking," said Kaname Gokon, a strategist with Okato Shoji Co in Tokyo.

US crude stocks dropped 14.5 million barrels last week to 511.4 million barrels, the biggest weekly drop in stockpiles since January 1999, according to government data.

Imports into the US Gulf Coast fell to 2.5 million barrels per day, the lowest since data collection began in 1990.

Traders said the imports fell as ships delayed offloading cargoes in Texas and Louisiana due to Tropical Storm Hermine.

Gasoline futures fell nearly 1% on Friday after jumping more than 5% in the previous session following the data release and on higher-than-expected draws and rising refinery utilisation in the Midwest.

Market participants shrugged off rising geopolitical risks, including an apparent North Korea nuclear test.

On Friday, Chinese data showed its consumer price inflation slowed to its weakest pace in almost a year in August, although an encouraging moderation in producer price deflation added to recent evidence of a steadying economy.

Russian average oil production rose close to 11 million bpd during 1 - 7 September, industry sources told Reuters, from 10.71 million bpd in August.

The oil options market indicates traders are not betting big on Opec and rival Russia clinching a meaningful deal this month to control output.

Opec and non-Opec producers such as Russia are expected to discuss the issue at informal talks in Algeria from 26-28 September.