A large deep-water deep-stratum gas field with reserves exceeding 50 billion cubic metres, the first of its kind in China, was discovered in waters southeast of Hainan Island, according to the China National Offshore Oil Corporation (Cnooc).

The gas field, dubbed Baodao 21-1, has a maximum operating depth of more than 1,500 metres and a completed well depth of more than 5,000 metres, Cnooc said on Thursday. It said the field is subject to extremely complex marine geological conditions.

The discovery of Baodao 21-1 marks important progress for Cnooc's technology in deep-sea deep-stratum exploration, the oil giant’s Hainan branch chief geologist Wu Keqiang said.

Cnooc added that it is the biggest drilling breakthrough in the Songnan-Baodao area in more than half a century.

"China's deep-sea and deep-earth exploration technology is world-class, and the discovery will not only further advance the development of related exploration technology, but also serve as a way for the country to showcase its advanced technology to the world," Lin Boqiang, director of the Center for Energy Economics Research at Xiamen University, told the Global Times.

Lin added the discovery is expected to further ensure China's energy security and meet the rising energy needs of its people. (CNS/Global Times)