On May 11, 2022, China's first domestically produced deepwater underwater Christmas tree was installed on the seabed in Yinggehai, Hainan. This equipment is an important part of the underwater oil and gas production system engineering demonstration project led by CNOOC. A key step has been taken in the development of key technical equipment for China's deepwater oil and gas development.

Subsea production system is the key equipment for developing deepwater oil and gas fields, including subsea wellhead, subsea Christmas tree, subsea control system, subsea manifold and other equipment. For a long time, only five European and American companies in the world have mastered the design and construction technology of underwater production systems, resulting in long procurement cycles, high prices, and difficult maintenance for the equipment. The 500-meter-level underwater oil and gas production system engineering demonstration application project implemented by CNOOC marks that China has the ability to design, construct and apply complete sets of equipment.

The underwater production system will be used to develop gas reservoirs around the Ledong platform of the Dongfang 1-1 gas field. The gas wells using the underwater production system can produce about 200 million cubic meters of natural gas per year.

Liu Shujie, chief engineer of CNOOC Hainan Branch, said that after the application of the underwater production system, the cost was reduced by about 27% compared with the previous one. Not only can the oil and gas reservoirs around the existing facilities that are not economically developed by independent platform development be effectively developed, but also the cost of deepwater oil and gas development will be greatly reduced, which is of great significance for accelerating domestic oil and gas exploration and development and improving the energy self-sufficiency rate.

Xie Yuhong, the chief scientist of CNOOC and the project manager of this scientific research project, introduced that in order to overcome this key technical equipment, CNOOC took the lead and cooperated with 16 units including CSSC Chongqing Qianwei to continue to tackle key problems in underwater production, underwater control, underwater production, etc. Monitoring and other key technologies, on the basis of years of technical accumulation, it took 36 months to master the design, manufacturing and testing technologies.Editor/Ma Xue