Recently, China Oilfield Services Limited (COSL) successfully completed the first real-well sea trial of its independently developed 1.25-grade and 2.0-grade deepwater drilling risers in the Pearl River Mouth Basin. These risers also passed in-depth inspections such as radiographic testing, which marks the first application of domestically developed risers in real wells in China, signifying that China now possesses the capability for independent design and manufacturing of deepwater drilling risers.
The deepwater drilling riser is a crucial core piece of equipment in deepwater oil and gas drilling operations, connecting the subsea blowout preventer to the floating platform during the deepwater oil and gas drilling operation.
As the connecting channel between the drilling platform and the subsea wellhead, the deepwater drilling riser has several essential functions. It isolates seawater, allows for the introduction of drilling tools and casing, facilitates the circulation of pressurized fluids such as mud and hydraulic oil, and enables the operation of the deepwater blowout preventer’s installation and retrieval.
The 1.25-grade and 2.0-grade deepwater drilling risers adopt high load-bearing locking block structure, with joint loads of 5,560 kN and 8,896 kN respectively, and the maximum operating water depth can reach 2,400 meters.
COSL gives full play to its leading role in the field of deep-water equipment industry, and started the core technology research of 1,500-meter deepwater drilling riser system in 2023, and successively broke through the core technology of multi-dimensional heavy-duty design of deepwater drilling risers, high-efficiency connecting and sealing technology, and high-performance anticorrosive process.
It is reported that the overall technical performance of COSL’s self-developed 1.25 grade and 2.0 grade drilling risers has reached the international level, which will lay a solid foundation for the subsequent development and engineering application of complete sets of deepwater deepwater drilling riser systems.