Offshore, polar, as well as deepwater oil as well as gas areas face severe solution problems such as wave, present, and also salt water deterioration, which need better needs than onshore pipes, as well as subsea oil and also gas pipelines usually have solution periods of more than twenty years, requiring using high-performance pipe steel. DNV-OS-F101 Seabed Pipe Specification has rigorous requirements on the transverse strength, longitudinal strength, low-temperature dynamic tear resistance, weldability, strain resistance and acid tool corrosion resistance of submarine pipeline steel.
offshore pipe laying
The lengthiest offshore pipe in the world is the Langeled natural gas pipe, which was laid between Norway and also Causation from 2004 to 2007, with a size of 1173km and also the deepest factor is 2775m. right here are offshore pipe design in recent years:
On May 23, 2020, the sea pipe of the Lingshui 17-2 job, China's initial deepwater gas area, was efficiently laid at 1,532 meters, damaging China's new document for sea pipeline laying as well as the very first operation at 1,500 meters of "ultra-deepwater". The job made use of more than 10,000 lots of undersea steel pipeline from Henggang, Hunan province. The simulation experiments of the outside stress of these deep-sea pipelines show that the steel tube can endure 35Mpa and also can be made use of for external pressure over 35m water depth.
The deepwater steel pipe is identified by large wall thickness about outer diameter ratio, high dimensional precision, etc. This is because the submarine pipeline has actually been in service in the marine environment of reduced temperature level, high pressure and solid corrosion for a long time. It not only bears a tons of inner and exterior pressure, axial force as well as flexing minute but also bears the vibrant lots of alternating external pressure, wave and present. The Helpful site stamina, wall surface density, and also dimension roundness of steel pipe are particularly important to avoid pipe damages. Meanwhile, with the continuous boost of pipeline laying deepness and also conveying pressure, high steel quality, huge pipe size, and large wall surface density are the growth fad for the offshore pipe.