Slowing imports from China have pushed the volumes of Iranian oil held in tankers at sea to the highest level in two and a half years. The volume of Iran’s crude in floating storage has jumped in recent weeks and widened the discount of Iranian grades to international benchmarks. As many as 52 million barrels of Iranian oil is stashed on tankers at present, nearly double compared to October, according to data from energy flows intelligence firm Kpler cited by Bloomberg. In comparison, early this year the volumes of Iranian…