CNOOC announced that the proved gas in-place of Baodao 21-1 Gas Field has successfully passed the Chinese governmental review and filing. Baodao 21-1 gas field is located in Baodao Sag, Qiongdongnan Basin, Western South China Sea. The water depth ranges from 660 to 1,570 meters. The main gas-bearing layer is the Paleogene Lingshui formation and the discovery is condensate gas reservoirs. The discovery well Baodao 21-1-1 completed at hole depth of 5,188 meters, encountering 113 meters of pay zone. The well is tested to produce an average of 587,000 cubic metres of natural gas per day. Chinese governmental bodies reviewed the discovery and certified the proven in-place of natural gas and condensate oil at over 50 billion cubic metres and 3 million cubic metres respectively. Baodao 21-1 gas-bearing structure will host the first deep-water deep-stratum large gas field in the South China Sea, realising the biggest discovery in more than half a century in Songnan-Baodao Sag. It will lay a solid foundation for the construction of a gas production base of trillion cubic meters resources in the South China Sea. The review and filing once again confirmed the exploration potential of this structure.