Recently, the news that China's largest liquefied natural gas (LNG) reserve base has been completed was featured on CCTV's news channel. The six 270,000-cubic-meter LNG storage tanks of CNOOC's Yancheng "Green Energy Port"—the world's largest single-tank capacity LNG tanks—simultaneously achieved mechanical completion in Yancheng, Jiangsu Province.
At the construction site, the Jiangsu Binhai LNG Phase I Expansion Project general contracting team (hereinafter referred to as the "Jiangsu Project Team") of CNOOC Petrochemical Engineering Co., Ltd. (hereinafter referred to as "CNOOC Petrochemical Engineering") was filled with joy. Since construction began in June 2021, CNOOC Petrochemical Engineering, as the lead general contractor, has spent three years turning the country's first batch of 270,000-cubic-meter LNG tank clusters from blueprints into reality, advancing the localization of independent design and construction technology for this green energy super project, and firmly securing its position in the top tier domestically in LNG terminal general contracting technical capability.
　　"Smart" Blueprint: Advancing the Engineering Transformation of the Chinese Solution Tailored to Local Conditions
　　China is vigorously promoting green and low-carbon economic and social transformation, and natural gas, as a clean energy source, is widely used. CNOOC actively advances the construction of "Green Energy Ports" in accordance with the national requirements for building a natural gas production, supply, storage, and sales system. "Green Energy Port" means a green energy port, which aligns with the green energy supply guarantee mission of LNG terminals.
　　"CNOOC Petrochemical Engineering actively participates in the design and construction of 'Green Energy Ports,'" said Wu Guangzeng, General Manager of CNOOC Petrochemical Engineering. "Since 2007, CNOOC Petrochemical Engineering has participated in the technical consulting, design, or construction of nearly half of the domestic LNG terminals, witnessing the leap in terminal tank scale from 30,000 cubic meters to 160,000 cubic meters, 220,000 cubic meters, and then to 270,000 cubic meters, and gradually mastering the independent design and construction technology for LNG terminals."
　　Compared with 220,000-cubic-meter LNG tanks, 270,000-cubic-meter LNG tanks have greater advantages in storage performance and economic efficiency. The Jiangsu Project Team of CNOOC Petrochemical Engineering is responsible for the design, procurement, construction, and commissioning of the Yancheng "Green Energy Port" Phase I Expansion Project. The blueprint of the "Green Energy Port" Phase I Expansion Project posted in the office of Project Manager Shi Houzeng is covered with markings, and the edges of the paper are slightly curled from wear. "Building the first batch of 270,000-cubic-meter LNG tank clusters, the leap in tank capacity has placed higher demands on design and construction," said Shi Houzeng. "With our rich design and construction experience, we are advancing the engineering transformation of CNOOC's CGTank large-scale LNG tank technology—a Chinese solution—tailored to local conditions."
　　"We combine CNOOC's independent technology with actual construction conditions to achieve engineering implementation and carry out design tailored to local conditions," said Shang Lijuan, Design Manager of the Jiangsu Project. "During the peak installation period on site, the design team focused on the process plant area design, which is most closely connected with the Phase I project, and concentrated efforts on key challenges. Design representatives were stationed at the construction site on a permanent basis to conduct technical coordination at any time, adjust design parameters according to site conditions, and ensure design quality."
　　The design team of CNOOC Petrochemical Engineering adopted digital design to draw a smart blueprint. By applying an engineering design integration platform, disciplines such as process, piping, and equipment achieved online collaborative design, integrating design process data, improving data accuracy and completeness, and enhancing design efficiency. Full-process 3D model design was realized, visually displaying the design layout of tanks and terminals—from the internal and external details of a 270,000-cubic-meter tank down to a single bolt, everything is clear at a glance, better guiding project construction.
　　Smart Construction: New Technologies and Processes Build High-Quality Projects
　　Storage tanks are core equipment in the LNG industry chain. Not only is the stored medium at an extremely low temperature—LNG at -162°C—but the tanks must also withstand extreme conditions such as fire, explosion, and earthquakes, placing extremely high demands on construction technology. During the construction of the Yancheng "Green Energy Port" project, new technologies and processes were innovatively adopted to build a high-quality project through smart construction.
　　The Yancheng "Green Energy Port" project is located at the mouth of the ancient Yellow River, where the underground soil is entirely soft silty clay. A single tank weighs more than 80,000 tons, and since the tanks contain LNG at -162°C, the maximum load-bearing capacity of the site for the six 270,000-cubic-meter LNG tanks exceeds 1.3 million tons. How can the tanks stand firmly?
　　"The bottom of each tank is firmly supported by 406 pile foundations with a diameter of 1.5 meters and a length of 75 meters," said Yang Yonggang, Chief Engineer of the Jiangsu Project. The project adopted integrated pile-forming technology for the first time, casting the 75-meter-long pile foundations in a single pour. It used a "long-distance satellite positioning pile-driving positioning system" to intelligently control and improve the precision of pile foundation construction, firmly supporting the tanks with a solid foundation.
　　The inner tank of the storage tank is equivalent to the inner liner of a thermos bottle and is the most important factor in ensuring the low-temperature performance of the LNG storage tank. The inner wall plate of the 270,000-cubic-meter LNG tank is nearly 45 meters high and weighs nearly 4,000 tons, involving a large amount of welding work, high technical requirements, and extremely difficult installation.
　　Yang Yonggang, Chief Engineer of the Jiangsu Project, said: "We implemented full-process supervision, using precision testing equipment such as ultrasonic thickness gauges and total stations to conduct acceptance inspection plate by plate and layer by layer, successfully controlling the error of the main installation parameters of the inner tank wall plates to within 1 millimeter." In addition, a fourth-generation intelligent welding inspection system was applied, using AI intelligent image interpretation, which improved welding progress and quality. The first-pass welding qualification rate of the inner tanks of the six storage tanks reached 99.51%, higher than the industry average of 96%.
　　The six 270,000-cubic-meter LNG storage tanks were built simultaneously, involving a huge amount of work: more than 1,056,000 cubic meters of concrete and more than 93,000 tons of steel were used—enough steel to build two Bird's Nests. During the peak construction period, dozens of trades provided technical support on site, with a total of 18 major construction units and more than 1,860 construction personnel. "We use the project management system to achieve standardized and refined management throughout the entire cycle of design, procurement, and construction," said Zhang Zhongfu, Deputy General Manager of CNOOC Petrochemical Engineering. The Jiangsu Project Team built a "smart construction site" at the project site, comprehensively and continuously tracking the working status of equipment and personnel, making the entire construction process traceable. "QR code intervention" was linked with the "smart construction site," enabling hazard identification and rectification to be handled "by code," and visual dynamic management of more than 640 construction machines and tools.
　　While building the physical project with high quality, the Yancheng "Green Energy Port" Phase I Expansion Project started with full-discipline digital design and implemented digital delivery throughout the entire construction process, creating a digital "twin" for this super project.
　　Together with its partners, CNOOC Petrochemical Engineering created a multi-dimensional visual digital integration platform for the Yancheng "Green Energy Port." From design and procurement to construction and commissioning, the data, documents, and models generated at all stages of the project can be clearly viewed through the platform. At the same time, centered on the digital and intelligent transformation of full-chain LNG production management, it reshaped the production process, achieved refined management of energy flow monitoring and carbon footprint, and built a smart "Green Energy Port."