But prices were still on track for weekly losses of up to 1.9 percent amid concerns that rising US production could undermine OPEC-led supply cuts.

By 1:32 p.m (1832 GMT), Brent crude was up 99 cents or 1.6 percent at $63.25 a barrel, but heading for a weekly slide of 0.9 percent.

US West Texas Intermediate (WTI) crude was at $57.25 a barrel, up 56 cents or 1 percent on the day and on track for a 1.9 percent loss on the week.

China's crude oil imports rose to 9.01 million barrels per day (bpd), the second highest on record, data from the General Administration of Customs showed.

"We have good numbers out of China," said John Macaluso, an analyst at Tyche Capital Advisors. "A lot of the extra imports are not from Saudi Arabia. Iran, Russia and the US are some of the countries picking up the slack."

Booming demand will push China ahead of the United States as the world's biggest crude importer this year.

US investment bank Jefferies forecast 2018 global oil demand growth of 1.5 million bpd, driven by almost 10 percent demand growth in China.

"Generally speaking, the market is looking more healthy than sick," said Tamas Varga, analyst with PVM Oil Associates.

Varga said the threat of a strike later this month from a union in Nigeria, Africa's largest oil exporter, was supportive.

An extension to the end of 2018 of production cuts by the Organization of the Petroleum Exporting Countries, Russia and other producers underpinned the market.

The output cuts pushed oil prices higher between June and October, with Brent gaining around 40 percent.

"Even if you have no bullish view OPEC and Russia have taken away the risk to the downside," said Bjarne Schieldrop, chief commodities analyst with SEB Bank, adding it was unlikely that Brent would drop below $61 per barrel.

Still, data this week showed that US crude output had risen 25,000 bpd to 9.7 million bpd in the week to Dec. 1, the highest production since the 1970s and close to the production levels of Russia and Saudi Arabia.

US energy companies this week added oil rigs for a third week in a row, the longest string of increases since summer, as higher crude prices prompted drillers to return to the well pad after a break in the autumn.

Drillers added two oil rigs in the week to Dec. 8, bringing the total count up to 751, the highest level since September, General Electric Co's Baker Hughes energy services firm said in its closely followed report on Friday.