As current oil reserves start to deplete, companies are looking to exploit deeper deposits. At these greater depths composite risers, with their high strength-to-weight ratio, reduce the effective tensions and bending moments compared to steel risers. However, there is still limited research into their behaviour, with one key missing element being a comparison with traditional riser designs which accounts for variances in material properties and wave loads. This paper therefore conducts a strength-based reliability analysis of composite catenary risers operating between 1,500 m and 4,000 m. A static global catenary model is combined with Classical Laminate Theory to determine the extreme response and its performance is verified against FEA. This response is evaluated with the Tsai-Wu failure criterion to determine first-ply failure. The effect of laminate moisture absorption on the long-term reliability of submerged composite-based risers is also investigated as it can cause a significant reduction in the strength of composite risers. The reliability analysis is conducted using the Monte Carlo Method, revealing that the composite risers perform well at 4000 m. The degradation in performance from moisture absorption becomes increasingly important at greater depths and needs further investigation for these applications.

随着当前石油储量开始枯竭，公司正在寻求开发更深的矿藏。在这些较大的深度，与钢制立管相比，具有较高的强度重量比的复合立管降低了有效的拉力和弯矩。然而，对其性能的研究仍然很有限，其中一个关键的缺失要素是与传统立管设计的比较，传统立管设计考虑了材料特性和波浪载荷的差异。因此，本文对在1,500 m至4,000 m之间运行的复合悬链立管进行了基于强度的可靠性分析。静态全局悬链线模型与经典层压理论相结合，以确定极限响应，并根据FEA验证了其性能。用蔡-吴故障准则评估该响应以确定第一层故障。还研究了层压板吸水率对浸没式复合立管的长期可靠性的影响，因为它可能导致复合立管的强度显着降低。使用蒙特卡洛方法进行可靠性分析，结果表明，复合立管在4000 m处表现良好。在更大的深度，由于吸湿而导致的性能下降变得越来越重要，并且对于这些应用需要进一步的研究。