"We are seeing a very steep backwardation in the September-October contracts - the last time it was that high was in 1990 after the start of the Iraq War," said Olivier Jakob, analyst at Petromatrix.
"So all the flows are going into WTI because of the backwardation," he added. The August WTI contract is to expire on Monday.
Analysts paid close attention to Federal Reserve Chairman Ben Bernanke's comments on Thursday when he testified before Congress for the second time in two days. Bernanke said recent unemployment and inflation levels suggest that the central bank needs to maintain a "highly accommodative monetary policy for the foreseeable future."
The market also watched geopolitical developments in the Middle East, as the African Union warned on Thursday that Egypt risks being engulfed in a civil war unless its newly installed interim government expands to include Islamists.