Project: Liwan 3-1 Gas Field Project

Time of completion: June 2013

Project introduction: Liwan 3-1 gas field, jointly developed by CNOOC and Husky Energy, is China’s first deepwater gas field. It is located in the Pearl River Mouth Basin, about 250km to southeast of Hong Kong, where the water depth ranges between 1,350m and 1,500m. A jacket weighing about 30,000 tons and a central platform weighing about 32,000 tons were constructed in 190m deep water and connected to the subsea production facilities at depths of 1,350-1,500m through a 6 inch submarine pipeline. Natural gas was transferred to the onshore LNG terminal on Zhuhai Gaolan Island through a 30 inch submarine pipeline.

Project highlights: Liwan 3-1 gas field is China’s first deepwater gas field with water depth of more than 1,000m. It is regarded as a marking of COOEC marching towards the deepwater field. During the execution of this project, COOEC independently developed the technology for the overall hoisting and weight transfer/lowering of 30,000 tons modules, used tower frames for the lifting and installation of large modules for the first time, and independently completed the design of the loadout, transport and offshore float-over installation of 30,000 tons modules for the first time, making a large number of achievements in installation design.