sentences:  Four years later, by which time Shell Canada had been wholly acquired by its parent, Royal Dutch Shell, the company applied to build a massive oil sands upgrading complex at the site of its Edmonton refinery.The project, which could cost as much as $27-billion, would be built in four stages.Like its existing upgrader, Shell's new facility would process bitumen from the Athabasca Oil Sands Project, as well as bitumen from steam-driven "in situ" oil sands projects.