Energy transition from the current fossil fuel-based economy to the renewable and sustainable technology era is one of the most important challenges of the future. Different promising options are being investigated, with particular attention to carbon capture & storage and hydrogen-based energy systems. Onshore and offshore pipelines have been identified as the primary mean for H2 transport and need to be investigated under different aspects. Many studies and experimental tests on metals are available in literature, however the call to advance the technology and close the gaps to make hydrogen transport offshore a viable option has matured in the last years.
Scope of the paper is to present the activities carried out by SAIPEM (EPCI Contractor) to investigate and assess the behaviour of materials and coatings used for subsea pipelines transporting hydrogen.
In literature, there are several studies and test results, however there are knowledge gaps for the offshore application. In addition, there are no comprehensive standards including detailed coating requirements specific for hydrogen or hydrogen/natural gas mixtures.
Therefore, a dedicated testing program based on offshore pipeline materials and coatings has been prepared. Main target of the testing programs is the assessment of pipeline materials, circumferential welds and internal coatings for H2 transport.
The paper explains the rationale behind the weld testing and in particular the girth welds. The selection process of tests conditions included the analysis of the most interesting hydrogen blending options in offshore transport operating scenarios to achieve a final partial pressure of H2 for testing that could be representative of the future offshore hydrogen transport development.
The test methodology, samples preparation and procedures along with the status of tests are discussed, and the following steps foreseen to complete the test campaign are presented.
