China News Service, Tianjin, July 18 (Wang Zaiyu Wang Junyan) The reporter learned from CNOOC Tianjin Branch on the 17th that China's first self-developed shallow water underwater Christmas tree system development project was successfully ignited in the Jinzhou 31-1 gas field in the Bohai Sea. The natural gas dragon buried more than 2,000 meters underground is stably transported to the platform flare arm through the underwater Christmas tree system. The test gas production volume of a single well reaches 310,000 cubic meters per day, which can be used by 1,500 families for one year.
Bohai Oilfield is China's largest crude oil production base, an offshore gateway to the opening up of northern China and an important support for the economic and social development of the Bohai Rim region. The fishery, shipping and oil and gas development industries are developed, and the multi-functional sea area overlaps.
China's first self-developed shallow water underwater Christmas tree system development project was successfully ignited in the Jinzhou 31-1 gas field in the Bohai Sea. Photo courtesy of CNOOC Tianjin Branch
Since 2019, CNOOC has started to carry out technical research on shallow water underwater production systems, exploring new development models of Bohai Oilfield, and plans to replace the jacket platform on the sea with the underwater production system, so as to realize the operation without affecting shipping and other applications. Effectively develop oil and gas resources in the case of sea demand.
Yu Guimin, Deputy General Manager and Chief Engineer (Drilling and Completion) of CNOOC Tianjin Branch, introduced that at present, there are more than ten oil and gas blocks in the Bohai Sea whose reserves are restricted. It has contributed a very important force to the production of 40 million tons of oil equivalent in the Bohai Oilfield.
The underwater Christmas tree is one of the indispensable core equipment of the underwater production system. It connects the oil and gas from the depths of the formation and the external oil and gas transportation pipelines. It can control the oil and gas production speed, monitor and adjust the production in real time, just like It is an intelligent "faucet" at the wellhead of oil and gas fields.
For a long time, only a few European and American companies in the world have mastered the design and manufacture of underwater Christmas trees.
China's first self-developed shallow water underwater Christmas tree system development project was successfully ignited in the Jinzhou 31-1 gas field in the Bohai Sea. Photo courtesy of CNOOC Tianjin Branch
The independent research and development of China's first shallow-water underwater Christmas tree is faced with the difficult challenges of new technologies, new equipment and new models.
To this end, CNOOC formed a joint research team, which took three years to overcome the technical difficulties of the shallow water underwater production system, and the localization rate reached 88%.
The total growth width of the underwater Christmas tree is 3.3 meters, the height is only 2.65 meters, and the overall weight is 24.8 tons. Compared with the conventional underwater Christmas tree, the height is reduced by nearly 25% and the weight is reduced by 35%. It is compact and lightweight. , At the same time, a "full wrap" type external protective device is specially designed, which can effectively avoid safety risks such as fishing net dragging and ship anchoring, and is more suitable for shallow water use.
The overall design concept is at the international leading level, and the entire system can operate normally on the seabed for 15 years.
Mi Lijun, general manager of CNOOC Research Institute, said that the successful independent research and development of China's first localized shallow water underwater Christmas tree system has solved the problem of oil and gas development in the Bohai Sea, and can also provide new opportunities for the development of similar oil and gas fields in other sea areas at home and abroad. The solution is of great significance for improving energy self-sufficiency rate and ensuring national energy security.
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