Chinese State-owned oil and gas giant China National Offshore Oil Corp (CNOOC) has tapped commercial flows of oil and gas from a shale exploration well in the South China Sea, the first successfully drilled shale oil well offshore.

Marathon Oil used to represent everything that was wrong with U.S. shale: enormous debtloads, lavish executive pay and a seeming willingness to spend whatever it took to boost output. The company hemorrhaged money, and the stock plunged 84% from a peak in 2014 through the end of last year.