On November 15, 2021, China's first shallow water underwater Christmas tree system independently developed by CNOOC obtained the product conformity certificate issued by DET Norske Veritas, marking that the shallow water underwater Christmas tree system independently researched and developed by China meets international standards and has the conditions for engineering demonstration and application in offshore oil and gas fields.

In May this year, CNOOC announced that the first shallow water underwater Christmas tree system independently developed by China was successfully tested in the Bohai Sea, which verified the reliability, safety and functionality of the system.

Christmas tree is used to block underground oil and gas and control the production of oil and gas wells. It is one of the core equipment in the process of oil and gas production, and is called the "throat" of formation oil and gas to transportation pipeline.

Compared with similar foreign products, the developed shallow water underwater Christmas tree system has a significant reduction in height and weight, fully reflects the characteristics of compact and lightweight, reduces the cost by nearly 40%, and the cost of a single set can be reduced by more than 15 million yuan; The "all wrapped" protection device specially designed for the Bohai Sea environment can effectively avoid fishing nets and anchor towing.

It is reported that the developed shallow water underwater Christmas tree system will be demonstrated and applied in Jinzhou 31-1 gas field in Bohai Sea in 2022. The introduction of shallow water subsea Christmas tree system in the Bohai Sea will drive the transformation of the inherent development mode of shallow water subsea oil and gas fields from the traditional jacket platform development to the underwater production system operation mode. The establishment of a new operation mode will solve the sea use contradiction of oil and gas development in the Bohai Sea Limited by environmental protection, navigation and other factors.