On May 14, 2021, China National Offshore Oil Corporation (hereinafter referred to as "CNOOC") announced that after nearly a hundred rigorous tests, the first shallow-water underwater Christmas tree system independently developed by my country was tested in the Bohai Sea. Successfully verified the reliability, safety and functionality of the system. This move is an important leap in the localization of key core equipment for my country's offshore oil and gas development, and marks my country's major breakthrough in the field of offshore oil engineering equipment.

The underwater Christmas tree system is the core equipment for offshore oil and gas field production. It connects oil and gas from deep in the formation and external oil and gas transportation pipelines. Through it, it can control the speed of oil and gas extraction, monitor and adjust the production situation in real time. my country is rich in marine oil and gas resources. Most of the reserves are limited by environmental impacts. The conventional development model of installing Christmas trees on offshore platforms cannot be adopted. Moving the Christmas tree system underwater is an important means to develop these reserves. "Underwater Christmas tree system is the'throat' of offshore oil and gas production, and is an indispensable key equipment in the underwater development mode of offshore oil and gas fields. Its manufacturing process and quality level are directly related to the safety, reliability, and economy of oil and gas field development. And environmental protection.” said Mi Lijun, project chief of CNOOC Research Institute Co., Ltd.

For the first time, the underwater Christmas tree system independently developed by China adopts full-wrapped protective facilities, which can effectively avoid the risks caused by the dragging of fishing nets and the lowering of anchors to the underwater production system. The design concept is at the internationally leading level. Compared with similar foreign products, the system has my country's independent intellectual property rights, breaking the long-term monopoly of a few western oil companies. The system has reduced weight by 40% and cost by 30%. Taking the underwater wellhead in the underwater Christmas tree system as an example, it can save 20% of the operation cycle of a single well and save about 6 million yuan in operation costs. The underwater Christmas tree system is planned to be officially applied in the Jinzhou 31-1 gas field in the second half of 2021, thus opening up a new situation in the application of domestically produced underwater Christmas trees.Editor/Xing Wentao