China has become the world’s third largest shale gas producer after the U.S. and Canada, delivering an output of 7.88 billion cubic meters in 2016, according to a recent press conference of the Ministry of Land and Resources.

The Fuling shale gas field, located in southwest China’s Chongqing municipality, has a proven reserve of 600.8 billion cubic meters, the world’s second largest shale gas field after the U.S. The gas field aims to raise its annual shale gas output to 10 billion cubic meters by the end of this year.

In the future, China is likely to build two shale gas bases, one in the southwestern city of Zunyi in Guizhou province and the other in Yichang City in Hubei province.

Shale gas is natural gas that provides a new clean energy source. In 2011, the State Council of China categorized shale gas as the country’s 172nd mineral asset and started to manage the gas as an independent mineral resource. The U.S. started to explore shale gas in the 1980s.