The second phase of Shenhai Yihao, China's first self-developed ultra-deep-water gas field, saw the onshore manufacturing of its integrated processing platform completed in Qingdao, Shandong province. [Photo/Chinanews.com]

The second phase of Shenhai Yihao, China's first self-developed ultra-deep-water gas field, saw the onshore manufacturing of its integrated processing platform completed in Qingdao, Shandong province, 15 days ahead of schedule, said its operator China Offshore Oil Engineering Co Ltd on Feb 1.

The Shenhai Yihao project, which started production in June 2021, has a natural gas proven reserve of over 100 billion cubic meters, making it the deepest and most challenging offshore ultra-deep-water gas field independently developed by China.

The second phase of the project is located in the Qiongdongnan Basin in the western part of the northern South China Sea, about 132 kilometers from Sanya, Hainan province, and about 70 km from the Shenhai Yihao energy station, with a water depth of nearly 1,000 meters.

Its integrated processing platform consists of a jacket and top block, with a total height of about 136 meters and a total weight of 12,215 tons, of which the top block consists of two parts, east and west, with 57.5-meter long and 36-meters wide deck plane.

According to Guo Qing, the general contractor project manager of Shenhai Yihao Phase II, the integrated processing platform applies a number of sets of domestically produced equipment with completely independent intellectual property rights, such as 7-megawatt gas turbine generator sets, and carries China's largest domestic offshore platform section plug flow trap, which is used to eliminate liquid level fluctuations and blockage risks in oil and gas mixing pipelines, and to ensure the reliable operation of oil and gas processing equipment.

Yu Faling, deputy manager of platform department of Shenhai Yihao Phase II project, said the project includes 13 key facilities, including a new integrated processing platform, an underwater production system, 5 submarine pipelines and 4 umbilical cables, etc. The project adopts the oil and gas development mode of "underwater production system + shallow water jacket platform + deep water semi-submersible platform remote control system", deploying a total of 12 development wells, three of which are deep water high-pressure wells.

Once production starts, the peak annual output of the project will increase by 50 percent, making it an important source of gas to ensure China's energy security.