While Brent crude oil spot prices have increased as much as $7 per barrel (6%) since the chemical weapons incident in Syria on August 21, 2013, market fundamentals had been moving Brent prices higher even earlier. From mid-April to August 20, Brent crude oil spot prices increased almost $15 per barrel (15%) because of increasing global refinery demand coupled with record levels of unexpected crude oil production outages, notably in Iraq and Libya.

via Today in Energy http://www.eia.gov/todayinenergy/detail.cfm?id=12891