US Refiners Rely on Shale More Than Ever as Heavy Oil Supplies Dwindle

American refiners are relying on oil supplies from the country’s biggest shale basins more than ever as flows of denser varieties from places like Mexico and Canada ebb.

US fuelmakers are consuming the lightest oil diet on record, according to recent government data, leaning heavily on shale formations in Texas, New Mexico and North Dakota. The shift comes as heavy crude supplies are strained by falling production from Mexico, a trade spat with Canada and a de facto US ban on imports of Venezuelan oil.