On August 6, the world’s first 16-megawatt tension leg platform (TLP) floating wind turbine “Haiyou Anlan” (CNOOC Anlan), constructed by CNOOC Engineering, was successfully connected to the Lufeng Oilfield power grid, officially supplying green electricity directly to the offshore oil and gas field.
This is China’s first tension leg floating wind platform, and also the world’s tension leg floating wind platform with the deepest application water depth, the farthest offshore distance, and the largest single-unit capacity. The commissioning of “Haiyou Anlan” marks that China’s deep-sea floating wind power equipment technology has advanced to the forefront of the world, successfully exploring a new technical route for China’s offshore wind power development.
“Haiyou Anlan” is located in the Pearl River Mouth Basin sea area, 200 kilometers southeast of Shenzhen, with a water depth of 136 meters and an offshore distance of 136 kilometers. Its overall height is equivalent to nearly 110 stories of a building. It is equipped with a 16-megawatt typhoon-resistant wind turbine, independently designed and constructed according to the extreme working condition of withstanding a Category 17 typhoon, with a service life of 25 years. After commissioning, it is expected to provide 54 million kilowatt-hours of green electricity to the oilfield annually, equivalent to saving 15,000 cubic meters of fuel oil and reducing carbon dioxide emissions by 35,000 tons.
The tension leg floating wind platform is a large-scale floating equipment specifically designed and constructed for developing deep-sea offshore wind power, consisting of an upper floating body, a subsea anchor foundation, and a mooring system. The floating body provides buoyancy far exceeding its own weight to “push” upward, while the tension legs use vertically taut steel cables to “pull” the floating body downward, thereby firmly “pinning” the platform to the sea surface and reducing vertical heave and fore-aft pitching. Compared with semi-submersible platforms, tension leg platforms have outstanding advantages in stability and steel consumption per megawatt, and occupy a smaller sea area, greatly alleviating the conflict between offshore wind power development and traditional marine utilization activities, and will be more conducive to the efficient and intensive use of marine space.
The tension leg floating wind platform is internationally recognized as the floating wind platform with the highest technical difficulty. A mature technical system has not yet been formed globally, with only one exploratory project in the mild Mediterranean sea area. Due to dense patent technology barriers, there is no prior application precedent in China.
CNOOC deeply practices the concept of green development, actively promotes industrial green transformation, strives to build “Green CNOOC,” focuses on the new business of deep-sea floating wind power, and relies on its first-mover advantages and technical accumulation in the field of marine engineering equipment. Based on the practical experience of China’s first deep-sea floating wind platform “Haiyou Guanlan” (CNOOC Guanlan), it has deepened the exploration of the tension leg technical route, carried out domestic localization research on the entire chain of equipment including mooring systems, wind turbines, and energy storage, and achieved first-time domestic application of multiple major technologies and products, providing another new path for the large-scale development of China’s deep-sea wind power.
“Haiyou Anlan” was designed according to the once-in-50-years typhoon working condition. It overcame a series of challenges including welding of ultra-large flanges and thick-plate dissimilar steels, high-altitude high-precision general assembly integration, and deep-sea large-diameter anchor pile mooring. It has fully mastered the complete set of core technologies for the design, construction, and mooring of large-megawatt floating wind power, with key structural dimensional accuracy of less than 2 millimeters, promoting a major breakthrough in China’s deep-sea floating wind power engineering construction capability.
“Haiyou Anlan” is also the world’s first wind power platform to apply an “all-steel-cable” tension leg system. Eight design schemes have obtained international authoritative certification, filling the domestic gap in high-precision construction technology for tension leg mooring systems. A total of over 70,000 meters of welds have been completed, with a first-pass welding qualification rate exceeding 99%.
The sea area where “Haiyou Anlan” is located faces complex sea conditions such as frequent typhoons. The steel cables must withstand severe tests such as enormous tension over the long term, and the mooring system operates under extremely demanding load conditions, posing enormous challenges in design and construction. CNOOC Engineering overcame the problem of fatigue failure of metal structures under high-frequency cyclic loading, broke through multiple technical bottlenecks in casting, forging, and processing and manufacturing. The connectors, ultra-large-specification permanent mooring steel cables, and matching cable sockets are world firsts, fully achieving independent controllability across the entire cycle of design, construction, installation, operation, and maintenance.
“Haiyou Anlan” has a total weight of 7,800 tons, and its swept area is equivalent to 7.5 standard football fields. The rigidity of the main structure and construction precision requirements are extremely high, and every step of construction, transportation, and reconnection faces enormous challenges. CNOOC Engineering independently developed a high-strength mooring system and a high-precision anchor mooring reconnection process, innovated a multi-equipment joint operation system involving the “Blue Whale 7500” and “Haiyang Shiyou 291” (Offshore Oil 291), applied a three-dimensional sea condition simulation system for dynamic monitoring of the construction process, and successfully achieved underwater millimeter-level docking, filling multiple technical gaps in the installation of tension leg floating wind platforms in China.
“Haiyou Anlan” is connected to the Lufeng Oilfield power grid through a submarine cable approximately 4.3 kilometers long. Due to the high volatility of wind power, CNOOC Engineering pioneered a combined power supply model of offshore wind power, fuel-oil power generation, and energy storage with multiple power sources working in coordination, achieving high-proportion integration of offshore wind power into the oilfield power grid, replacing crude oil power generation with green electricity, reducing the dependence of oil and gas production on fossil fuels, and also reducing pollutant emissions and carbon emission intensity. The integrated development of “oil and gas + wind power new energy” provides an important solution for China’s marine energy development and high-quality green transformation.
The successful implementation of “Haiyou Anlan” is not only a major breakthrough in China’s deep-sea wind power technology and marine engineering technology innovation, but also fully leverages the advantages of the new nationwide system for mobilizing resources, bringing together dozens of leading domestic industry enterprises and research institutes, establishing a collaborative innovation and joint implementation mechanism among central state-owned enterprises, private enterprises, and research institutes, focusing on systematic research in key core fields, forming economically feasible, replicable, and scalable technical routes and engineering solutions, driving the upgrading of China’s high-end offshore wind power equipment manufacturing industry, and laying the foundation for China to establish an independent and controllable complete industrial chain for deep-sea wind power.
