The price of US light crude oil reached more than $US100 per barrel on Wednesday - its highest for 14 months - on concerns over political turmoil in Egypt.
US crude rose $US1.64 to $US101.2 per barrel, its highest since May 2012 and Brent crude rose 1.76% to $US105.76 per barrel.
Rising demand for oil in the United States was also a factor in the rise.
The US Energy Department said that weekly US crude supplies fell by 10.3 million barrels.
That was the biggest fall in 13 years and was more than three times the drop that had been expected.
The BBC reports it was partly due to a temporary reduction in supplies from Canada as well as increased demand from a refinery in Indiana that had just restarted work.
Traders were also worried that the political situation in Egypt could interrupt oil flows through the Suez Canal and the Middle East, which account for around 25% of the world's oil output.