FILE PHOTO: A worker pours liquid oil into a barrel at the delayed coker unit of the Duna oil refinery operated by MOL Hungarian Oil and Gas Plc in Szazhalombatta, Hungary, on Tuesday, July 9, 2013. Oil extended losses below $60 a barrel amid speculation that OPEC's biggest members will defend market share against U.S. shale producers. Photographer: Akos Stiller/Bloomberg via Getty Images
