On the evening of October 19, 2022, CNOOC announced that it had made a major breakthrough in the exploration of Qiongdongnan Basin in the southeastern sea of Hainan Island, and discovered China's first deep-water and deep gas field, Baodao 21-1, with proven geological reserves of more than 50 billion cubic meters, realizing the biggest breakthrough in the Songnan-Baodao depression in more than half a century. It is a powerful progress in speeding up deep-sea exploration.

Oil test scene of Baodao 21-1 pre-exploration well

In the field of offshore oil and gas exploration, the water depth of more than 300 meters is generally referred to as deep water, and the well depth of more than 3500 meters is defined as deep well. The Baodao 21-1 gas field is located in the deep water area in the southeast of Hainan Island. The maximum operating water depth is more than 1,500 meters, and the drilling depth is more than 5,000 meters. It is about 150 kilometers away from the "Deep Sea No.1" ultra-deep water gas field, and the Marine geological conditions are extremely complex.

Oil test scene of Baodao 21-1 pre-exploration well

Since the foreign cooperation in the 1980s, CNOOC has not been afraid of complex geological conditions and has explored "treasure Island" for four times, but has not found large-scale discovery. Since entering the new era, CNOOC takes energy as the mission to serve the country, uses new exploration technology, goes deeper, explores the "treasure island" five times, and finally discovers a batch of new favorable structures. Through target selection, CNOOC researchers found that Baodao 21-1 has the structural background of large delta development, which is most likely to be a large and medium gas field. The first pre-exploration well deployed was drilled to 113 meters, setting a record for the thickest reservoir in a single well in deep water. After testing, the daily production of natural gas 587,000 cubic meters. The proved geological reserves of natural gas and condensate have exceeded 50 billion cubic meters and 3 million cubic meters respectively.

Offshore Petroleum 982 drilling Baodao 21-1 pre-exploration well

Wu Keqiang, chief geologist of CNOOC Hainan Branch, said, "As the formation deepens, the quality of basic data such as earthquakes deteriorates, and the difficulty of reservoir prediction, gas analysis and structure implementation increases exponentially, as well as the difficulty of drilling. The successful discovery of Baodao 21-1 not only confirms the exploration potential of Baodao Sag, but also indicates that we have made an important breakthrough in deep-water exploration technology, which has important guiding significance for the exploration of similar strata."

According to CNOOC's overall plan, by 2025, the total proved natural gas reserves of Yinggehai, Qiongdongnan and Pearl River Mouth basins in the South China Sea will reach 1 trillion cubic meters, and the "one trillion square atmosphere" will be built. Through the "Yacheng-Hong Kong" subsea gas transmission line, the largest in Asia, high-quality clean energy will be directly connected to the Guangdong-Hong Kong-Macao Greater Bay Area and Hainan Island, providing a strong guarantee for regional construction and energy structure transformation.

, deputy general manager of China's cnooc weeks with said: "China's cnooc will continue to increase the intensity of surrounding seas in hainan natural gas exploration and development, to speed up the pace into the depths of the sea, to discover the large and medium gas fields as the goal, to deepen the deep deep geological knowledge and technology innovation, to promote natural gas reserves accounted for, achieving high quality development contribution strength for the company." Editor/He Yuting