U.S. Petroleum storage tanks.

U.S. oil and gas production is evolving so rapidly—and demand is dropping so quickly—that in just five years the U.S. could no longer need to buy oil from any source but Canada, according to Citigroup's global head of commodities research.

Citigroup's Edward Morse, in a new report, projects a dramatic reshaping of the global energy industry, where the U.S., in a matter of years, becomes an exporter of energy, instead of one of the biggest importers.