Composite riser design and development – A review

There is accelerating interest in composite risers for deepwater applications. Composite risers offer much higher strength to weight ratios over metallic risers but there is less experience of their behavior in deepwater environments. A general review on current developments specific to composite risers highlighting the remaining challenges and the applications, design evolution, state-of-the-art modeling and experimental techniques is lacking. This paper provides such a review on fiber-reinforced polymer composite risers. The major issues for composite risers are addressed including the complicated combination of loads under harsh deep sea environment, the lack of long-term material degradation database for assessing the reliability of these riser systems and the need of effective numerical models to fully account for complex realistic loading configurations. The paper also highlights current gaps for design and application of composite risers in offshore technology and promising future research areas to help expand their utilization in deeper water. reinforced angle ply laminates bonded between a metallic/elastomeric inner liner and an outer liner made of thermoplastic or thermoset materials or metal alloys (Gibson, 2003). However, applications of FRP composite risers encounter many challenges. Some include the lack of full understanding of the mechanics and behavior of risers under deepwater environment, the lack of available S-N data for fatigue life prediction or the availability of full-scale testing of composite risers accounting for the scaling effects. The lack of knowledge imposes relatively high safety factors, from 15 to 50, for risers in the offshore as recommended by DNV (Det Norske