On September 28, as the Binhai 109 pipe-laying vessel completed the installation of the final end cap for a subsea pipeline in the southern Bohai Sea, China’s total length of subsea oil and gas pipelines surpassed 10,000 kilometers, placing it among the world’s leading nations.

　　China’s technological capabilities in subsea pipeline equipment have reached the international advanced level.

　　As the “lifeline” of offshore oil and gas development, subsea pipeline engineering is a highly sophisticated and cutting-edge field that integrates design, construction, installation, and operation and maintenance. Not only does it feature a complex technical system and extremely high construction difficulty, but it also poses rigorous challenges to technological equipment. With a series of key technological breakthroughs and the successful localization of critical components, China’s subsea pipeline engineering equipment technology has achieved a leapfrog development.

　　The seafloor is far from being a flat, uniform surface; instead, it features a complex interplay of seamounts, seamount hills, and oceanic trenches. The pipelines laid on the seafloor typically carry high-temperature, high-pressure oil and gas as their internal media, while externally they are exposed to extreme marine conditions and harsh geological environments—including wind waves, currents, typhoons, sediment transport, and geological faults. Ensuring their safe and stable operation over a service life of 20 years or even longer presents an enormous challenge.

　　He Yang, Deputy Director of the Design Institute of CNOOC Engineering, China National Offshore Oil Corporation: Through joint technological research and development, we have successfully mastered a comprehensive set of key technologies—including long-distance multiphase transportation of heavy oil and high-viscosity crude oil, autonomous design and installation of subsea pipelines under harsh marine conditions and complex topography, as well as emergency response and maintenance—enabling us to build a series of large-scale construction equipment, such as the 3,000-meter-class ultra-deepwater pipe-laying vessel Haiyang Shiyou 201. As a result, our operational capabilities have achieved a major leap—from shallow waters to ultra-deep waters.

　　China’s marine environment is complex, placing higher demands on subsea pipeline engineering technology. Since the start of the 14th Five-Year Plan, China has accelerated its efforts to achieve self-reliance and domestic production in technology, materials, and equipment. In 2023, domestically produced software for subsea pipeline calculation and analysis and fully automated welding equipment were successfully developed. In 2024, the world’s first kilometer-scale automatic pig launcher manifold—entirely developed by Chinese researchers—was put into operation. In 2025, the “Haiwei” system—a globally pioneering intelligent monitoring device for deepwater pipeline installation—completed its sea trials. Furthermore, significant breakthroughs have been made in the domestic production of pipeline materials and associated equipment.

　　He Yang, Deputy Director of the Design Institute of CNOOC Engineering, China National Offshore Oil Corporation: With the successive completion of a number of ultra-deepwater and high-pressure subsea pipelines, including the “Deep Sea No. 1” gas field, China’s technical capabilities in subsea pipeline engineering equipment have successfully reached the international advanced level and are at the forefront globally in terms of the completeness of its equipment technology system.

　　China’s Subsea Pipeline Engineering Goes Global

　　While accelerating the development of domestic offshore oil and gas projects, China is actively expanding into international markets and enhancing the global reputation of its “subsea pipeline engineering” brand in key international oil-and-gas cooperation regions such as the Belt and Road Initiative.

　　Since the beginning of this year, China’s overseas cooperation on submarine pipeline projects has been accelerating its implementation.

　　In July, offshore vessels such as “Haiyang Shiyou 202” and “Haiyang Shiyou 295” made their first-ever trip to Brunei to participate in subsea pipeline construction operations. In August, Asia’s first 3,000-meter-capacity crane-laying vessel, “Haiyang Shiyou 201,” completed the installation of the final 10-inch subsea pipeline for Qatar’s Phase 5-2 project. In September, the first subsea pipeline for the RUYA project in Qatar—constructed by CNOOC Engineering—was successfully laid, setting a new record for Chinese companies in terms of subsea pipeline installation speed in the Middle East region. This project represents the largest subsea pipeline engineering contract ever undertaken by a Chinese enterprise.

　　Gong Xuecheng, Deputy General Manager of the Installation Division of CNOOC Engineering, China National Offshore Oil Corporation: In recent years, CNOOC Engineering has undertaken more than 10 international subsea pipeline projects in countries including Nigeria, Saudi Arabia, Qatar, and Brunei. The company has laid over 500 kilometers of subsea pipelines in total, setting numerous industry records, such as the "largest diameter subsea pipeline" and the "heaviest single-length subsea pipe" worldwide.

　　Just last month, CNOOC Engineering secured a Qatari order worth approximately 4 billion U.S. dollars, setting a new record for the largest contract amount won by a Chinese company in the Middle East region for offshore oil and gas engineering projects. The smooth implementation of a series of international marine engineering projects has enabled China’s marine engineering enterprises to participate more deeply in global oil and gas cooperation, providing “engineering solutions” from China to support local energy infrastructure development and high-quality economic growth.