On April 12th, according to the official WeChat account of CNOOC (China National Offshore Oil Corporation), the heaviest and most complex three sets of deepwater subsea central pipe manifolds of the "Deep Sea No.1" Phase II project have been successfully installed, marking a significant progress in underwater engineering operations.
The "Deep Sea No.1" Phase II project of CNOOC is located in the Qiongdongnan Basin of the western part of the northern South China Sea, only 132 kilometers away from Sanya City, and about 70 kilometers away from the "Deep Sea No.1" energy station of the Phase I project.
This project is not only China's first deepwater high-pressure gas field project but also demonstrates China's outstanding strength in the field of deep-sea oil and gas exploration and development. Through in-depth exploration, the project has discovered natural gas geological reserves exceeding an astonishing 50 billion cubic meters, with operating water depths close to a kilometer, marking another major breakthrough in China's deep-sea oil and gas development.
In this project, 12 subsea gas wells are ingeniously deployed, and an advanced deepwater subsea production system is newly built. Among them, the subsea central pipe manifold, as the core technical equipment of the system, plays a crucial role.
It acts as an underwater "oil and gas hub," silently working among the wellheads to collect oil and gas resources from the deep sea, then transporting them to the platform, contributing to China's energy supply.
It is worth mentioning that all three sets of subsea central pipe manifolds in the "Deep Sea No.1" Phase II project have a total weight of over 540 tons, and the installation of each set has condensed the wisdom and sweat of numerous technical personnel. The first and second sets of manifolds were successfully installed at the end of last year and early this year, respectively.
The third set of subsea central pipe manifold (South Manifold), installed this time, is the heaviest in the project, with a hoisting weight of up to 187 tons. The installation accuracy requirement for such a huge subsea structure is extremely high, comparable to the docking of manned spacecraft in space.
In deepwater subsea operations, technical personnel need to face multiple challenges such as ultra-high hydrostatic pressure, unstable ocean currents, and dark seabed environments. To ensure the safety and stability during the installation of the central pipe manifold, technical personnel need to accurately monitor the status of the main hoist hook and counterweight blocks, while maintaining extremely high precision when aligning with the seabed and suction piles.
The commissioning of the "Deep Sea No.1" Phase II project will further increase the peak annual output of the gas field, with an expected increase of 50%, reaching an annual natural gas production of 4.5 billion cubic meters, adding new momentum to China's energy supply.
