The Jiaoshiba shale gas field in southwest China's Chongqing has become the second largest known field in the world, after the one in North America, according to the latest discovery by experts on land and resources.

China has newly discovered an additional 273.85 billion cubic meters of shale gas in Jiaoshiba shale gas field in Fuling, southwest China's Chongqing, bringing total proved reserves there to 380.6 billion cubic meters and the area of gas field to 383.54 square kilometers, according to latest assessment by experts from the Ministry of Land and Resources.

China is confident it will reach an annual capacity of 10 billion cubic meters because of this area by the end of 2017 on the basis of these newly discovered reserves, said a Sinopec official in charge of exploration.

Reserve quantities in the area are expected to expand as the exploration process goes on. This exploration marks the development and production of shale gas entering a large-scale, industrial stage.

The explored areas boast continuous gas reservoirs, shallow depth reserves, high formation pressure, good natural gas components and high gas well output.

Known reserves in Fuling can meet the demands of more than 20 million households in China.

Around 80 per cent of exploration devices are domestic made. Natural gas consumption in China makes up 5.5 per cent of primary energy consumption, far lower than the world average - 24 per cent.

The exploration work of shale gas will help improve natural gas self-sufficiency and optimize China's energy structure.