NBCNews.com | Hamm: Americans pay price for US oil export ban CNBC Billionaire oilman Harold Hamm said Thursday that U.S. refineries can't handle all the oil that's being produced domestically. "Basically, there's 18 million barrels-a-day refinery space and $12 million barrels a day has been set-up for heavy sour ... Oil Insiders Bullish For Their Own Stocks |