Surprising to many, Canada is the No. 1 oil exporter to the United States. Increasingly, these supplies come from Canada’s oil sands in northern Alberta. That province’s estimated oil sands deposits are in excess of 1.7 trillion barrels of crude bitumen. More than $91 billion has been invested in the oil sands in recent years and over $170 billion in oil sands-related projects. Venezuela and California are also heavy oil producers.