This undated photo provided by CNOOC shows the Lingshui 36-1 gas field in waters southeast of Hainan, China's southernmost island province. (CNOOC/Handout via Xinhua)

The original gas in place (OGIP) of the Lingshui 36-1 gas field -- the world's first large, ultra-shallow gas field in ultra-deep waters -- has been estimated at more than 100 billion cubic meters, according to the China National Offshore Oil Corporation (CNOOC).

CNOOC, one of China's three biggest oil companies, on Wednesday said that the relevant government authorities have approved the data.

The Lingshui 36-1 gas field is located in waters southeast of Hainan, China's southernmost island province.

The company has estimated that the OGIP of the Yinggehai, Qiongdongnan and Zhujiangkou basins in the South China Sea is more than 1 trillion cubic meters.