Two years ago, things were looking grim for refineries on the US east coast. Without pipeline links to the supplies of cheap oil coming from places such as the Bakken Shale in North Dakota, they were dependent on costlier seaborne crude, making them unprofitable. So when Sunoco, the Philadelphia-based refiner and fuel retailer, announced that it was seeking a buyer for its Girard Point and Point Breeze refineries in Philadelphia in September 2011, many analysts doubted it would find a buyer