Irish Times | Oil at $30 hurting insurance of shale drillers Irish Times Oil at $30 a barrel is blowing a hole in the insurance that US shale drillers bought to protect themselves against a crash. Companies including Marathon Oil, Noble Energy, Callon Petroleum , Pioneer Natural Resources, Rex Energy and Bonanza Creek ... Oil Drillers Exposed in Three-Way Hedges as Crude Dips Below $30 |