Sales abroad of crude oil, natural gas and petroleum products have reached more than 7 million barrels of oil equivalent per day (MMboe/d), representing a new industry for the U.S., according to Harold Hamm, who heads one of the nation’s largest independent oil and gas producers.

Crude oil exports alone may increase to 4 MMbbl/d by 2022, according to recent remarks by Enterprise Products Partners LP, as the world demands more light sweet crude. China has gone from taking just one cargo of under 1 MMbbl in the first eight months of 2016 to buying about 115,000 bbl/d from the U.S. so far this year, according to Reuters.