DESIGN DEVELOPMENT OF EFFICIENT JIONT STRUCTURE OF RISER PIPES MEDE OF COMPOSITE MATERIALS

目前，日本已经开发出适用于4000米深深水钻井的隔水管，同时也在研究2000米深的隔水管用于石油生产。然而，许多与发展有关的技术问题仍有待解决。钢立管系统的长度限制被认为是2000米，而更深度的立管钻井系统需要更多的开发元件。开发面临的问题之一是降低立管的重量。为了减轻重量，碳纤维增强塑料（CFRP）作为立管材料的替代材料正受到关注。使用CFRP带来的最大好处包括：由于其相对强度和刚度高、机械性能优异、疲劳强度好、耐腐蚀性能好，从而大大减轻了重量。因此，根据立管CFRP接头的结构特点和典型失效模式，对其进行了三维失效判据。将该问题简化为轴对称无扭问题，采用有限元法进行了失效模拟，并对CFRP提升管应用的可行性进行了研究。

Currently, riser pipes suitable for deepwater drilling at 4000-m depth have been developed in Japan, and riser pipes suitable for depths of 2000-m are also being investigated for use in the production of petroleum. However, many technical issues related to development still remain to be solved. The limitation in length of the steel riser pipe system is considered to be 2000-m, and riser drilling systems for greater depths entail a larger number of development elements. One of the development issues faced is the reduction in weight of the riser pipe. To achieve weight reduction, attention is now being focused on carbon fiber reinforced plastics (CFRP) as an alternative to steel as the material of the riser pipe. The best benefits derived by using CFRP include substantial weight savings because of the high relative strength and stiffness, excellent mechanical properties, good fatigue strength and high resistance to corrosion.So three-dimensional failure criteria were applied to the CFRP joint of the riser pipe based on its characteristic structure and typical failure modes. Failure simulation by FEM was performed by simplifying the problem to an axisymmetric torsionless problem, and the feasibility of application of the CFRP riser pipe was investigated.