Recently, China National Offshore Oil Wenchang 19-1N and 8-3E oil field productivity release projects in the South China Sea have been completed. This is the first time to lay stainless steel composite double-deck sea pipe in our country. The difficulty of operation is the most in our country. The two new welding technologies are also the first application.
This laying of stainless steel composite double-layer sea pipe is 4.92 kilometers long. The inner pipe is a 6-inch bimetal mechanical composite sea pipe with 3 mm stainless steel lining. The outer pipe is a 10-inch ordinary carbon steel pipe. The middle of the two layers of sea pipe is filled with a 30 mm thick insulation layer. The most important internal pipe is manufactured by the aviation material company affiliated to the Fourth Research Institute of Xi'an Aerospace Science and Technology Group Company, and the company also provides the overall solution for the site construction.
In this project, CNOOC initiated the butt welding process with narrow notch and zero gap, and the total qualified rate of welding quality was greatly improved. This not only proves that CNOOC has fully mastered the laying technology of composite pipes, but also proves once again that the product quality and construction scheme provided by CNOOC have met the strict standards of offshore oil.
In recent years, relying on the advantages of solid power technology, the Fourth Academy of Aerospace Science and Technology has vigorously developed dual-purpose military and civilian products and pioneered the production of bimetallic composite pipes in China by using space deflagration technology, which has significantly improved the corrosion resistance of pipes, prolonged their service life and low cost. As early as 2011, CNOOC broke the foreign monopoly in the international bidding of large-scale submarine gathering and transportation pipeline project, pioneered CNOOC's first use of domestic bimetallic composite pipelines in submarine gathering and transportation pipeline system, and achieved a breakthrough in the application of bimetallic composite pipelines from land to ocean.