US benchmark West Texas Intermediate for November delivery rose 31 cents to USD 91.18 while Brent crude for November also gained 33 cents to USD 97.30 in mid-morning trade.
Banking giant HSBC said early Tuesday its flash purchasing managers index (PMI) for the Chinese manufacturing sector came in at 50.5 in September, from a final reading of 50.2 in August.
A reading above 50 indicates growth and anything below points to contraction. Analysts had expected the figure to dip to 50.0. The index tracks manufacturing activity in China's factories and workshops and is a closely watched indicator of the health of the economy.
"What we are seeing with the Chinese PMI numbers is a strong rebound when analysts had actually priced in a possible contraction," Desmond Chua, market analyst at CMC Markets in Singapore, told AFP.
"The numbers released today bring about some sense of optimism as new orders and new exports in China saw marked improvement," he added.
Market sentiment in China has been weighed by a string of weak data for August, including a five-year low for industrial output growth and a surprise drop in imports, which have put in peril the government's target of 7.5 per cent annual economic expansion for this year.
Chua said prices will also be lifted after the Pentagon late yesterday announced that the United States and its "partners" have launched bombing raids for the first time against Islamic State extremists in Syria. Washington began air strikes against IS targets in Iraq on August 8.
The Islamic State (IS) group has overrun large swathes of Iraq and Syria and declared a "caliphate" in those areas. The sweeping offensive began on June 9, preventing Baghdad from exporting oil via a pipeline to Turkey and by road to Jordan.
In Syria, a three-year civil war between the government and insurgents including IS has seen production diminish from 400,000 barrels a day in 2010 to around 25,000 barrels a day in January, according to the US Energy Information Administration.