Abstract
Reeling installation of subsea pipelines has led to the application of this technology to an increasing variety of projects, as it significantly speeds up the laying process with major cost reductions. Within the hydrogen economy, the long-term vision includes hydrogen production offshore, with offshore hydrogen directly connected to wind farms and to offshore pipelines, where pipe reel-lay method shall be taken into account.
The main challenges of this laying method are that the significant plastic strain accumulated by the material may modify the material performance.
In the present work a X65QS seamless pipe has been tested in terms of fracture toughness and FCGR performance under H2 gas environment at 200 bara to identify material performance variation based on different reeling simulation cycles. Cycles to simulate intrados and extrados conditions have been applied and compared with the reference “as it is – not strained” as well as air condition. The results showed no significant difference between strained and “as it is – not strained” condition in terms of FCGR performance, but a slightly variation of the fracture toughness based on the applied straining cycle. This preliminary conclusion indicates good potential of use of QT seamless pipes for offshore hydrogen application.