An Iraqi worker opens a pipe at Sheaiba oil refinery in Basra in this March 29, 2007 file photo. World markets braced for more volatility on December 17, 2014 as tumbling oil prices and a brewing financial crisis in Russia sent investors stampeding for safe havens such as the yen and U.S. Treasuries. REUTERS/Atef Hassan/Files (IRAQ - Tags: ENERGY BUSINESS ENVIRONMENT)