【Ten Years of Rapid Development in Chemical Engineering Equipment】1462–2024: China’s first domestically developed subsea water injection tree put into use in Zhanjiang

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Happy New Year 2024 **********************【Ten Years of Progress in Chemical Processing Equipment】A continuously updated summary post is available; feel free to join the discussions at https://bbs.hcbbs.com/thread-3576046-1-1.html (Source: Haichuan Chemical Industry Forum) ***************** On February 6, 2024, CNOOC announced that China’s first domestically developed subsea water injection tree, a key piece of equipment for underwater oil production, was put into use in the Zhanjiang area. The deployment of this device marks a new step forward for China’s offshore oil industry in helping to reduce production declines in existing oil fields, and it holds great significance for promoting the high-quality development of this industry. The water injection tree is one of the core components of an oil field’s subsea production system; it connects the oil reservoirs deep in the formation to the subsea water injection pipelines on the platform. By using filtered seawater at a maximum pressure of around 17 MPa to drive oil out, it can effectively increase the production of mature oil fields. The underwater water injection tree put into use this time is 3.5 meters long, 3.2 meters wide, and 3 meters high, with a total weight of nearly 22 tons. Yan Bangchuan, project manager at CNOOC Zhanjiang Branch: At present, only a few companies around the world possess the capability to design and manufacture subsea water injection trees. The subsea water injection tree developed this time features light weight and low cost – its weight can be reduced by 40%, while costs can be cut by over 60%. With this water injection tree in use, it is expected that this well will be able to produce an additional 50,000 tons of crude oil. Experts told reporters that water injection development is one of the key measures to improve crude oil recovery rates and achieve high and stable oil production in oil fields. As oil is continuously extracted from beneath the seabed, the permeability of the underground oil reservoirs decreases and the formation pressure drops; as a result, the oil cannot flow out naturally. The water injection system acts like a \"syringe,\" injecting energy into the \"capillaries\" of the formation to drive oil and gas toward designated locations, thereby increasing oil and gas recovery rates. The newly deployed water injection tree features an innovatively designed hydraulic docking sleeve, which addresses challenges such as the accurate alignment between vertical water injection trees and tubing hangers. Meanwhile, in conjunction with the development of large-diameter, high-pressure water-blocking risers, this design solves the problem of incompatibility when installing subsea wellheads on jackup platforms, thereby effectively improving operational efficiency. Huang Yi, Deputy Chief Engineer of CNOOC Zhanjiang Branch: The oil recovery rate in the Beibu Gulf is generally between 20% and 30%. The use of these subsea water injection systems can increase the recovery rate of the target oil reservoir by about 10%, meaning that for every 1,000 tons of proven oil reserves, an additional 100 tons of oil can be extracted. Subsea water injection trees have good potential for application at sea and serve as a model, which will be highly beneficial in promoting the development of China’s marine oil and gas-related industries.