Zoe BollingerOct 20, 2014Science and Technology Oil drops below $86 on over-supply and global economy worries Oil drops below $86 on over-supply and global economy worries | ReutersCALGARY Alberta (Reuters) - Brent crude fell below $86 a barrel on Monday as nagging concerns about abundant supply and sluggish demand pushed the global oil benchmark back down toward a four-year low