Material Selection and Challenging for Offshore Linepipe Application Free

Design in offshore production is more and more facing challenging situations. Deeper fields and water depths, higher pressure and temperature, corrosive internal and external environments, geo-hazard push technological solutions beyond their limits. Linepipe material selection is one of the key step and must be properly considered along the design chain so to reduce failure risk during the whole life of the component under consideration. When demanding projects are considered, actual conditions could not be covered by internationally recognized standards and guidelines and achievement of the adequate level of safety has to be guaranteed by specific data managed by designer and operators. Special material requirements should be requested and validated through a devoted laboratory testing program and, in some cases, also by full scale testing reproducing actual laying and operative conditions. This paper presents the main areas of concern regarding material selection and how a proper testing program can be effective in supporting such selection. As corrosion and stress-corrosion, fracture, high pressure, temperature and deformation are the main driving factors which lead the material choice, the proper testing program supporting the most challenging offshore linepipe projects will cover all the failure modes related to those factors. Some examples will be given showing how a proper material selection can make the difference.