As the oil and gas industry turns to the deep sea, flexible risers are becoming more and more widely used. To effectively achieve the lightweight and high strength requirements of ultra deep-water oil and gas development, it is a new trend to replace steel with CFRP. For deep-water flexible riser systems, the riser is bearing axial load, bending, and pressure during installation and operation, which may lead to local buckling. The carbon fiber reinforced material replaces the steel of tensile armor with a higher strength-to-weight ratio compared to metal risers, but its performance in deep water environments is less experienced. Firstly, this paper mainly describes the buckling behavior of a flexible riser, a 3D FE model was established by using ABAQUS to study the radial buckling mechanism. Then, to study the influence of different conditions on the buckling behavior through numerical simulation. Finally, the results of the finite element model are compared with the experimental data to provide some theoretical experience for the actual design and manufacture of CFRP in a flexible riser.
Since the 21st century, resource development has gradually moved from land to sea. Flexible riser plays a key role in the development of deep-sea oil and gas resources. The traditional flexible riser is mainly made of the structure layer of metal materials and the functional layer of polymer materials. The structure layer is mainly made of high-strength steel such as carbon steel, stainless steel, etc. Nowadays, Resource development moves to the deep sea from the shallows gradually, and the weight of the flexible pipe has increased following the deepened of oil and gas exploitation, so comes with the broader size of the platform. Traditional steel is with deficiencies like short service life and complicated maintenance in the face of high-temperature corrosion of oil and gas. To solve these problems, people turn to fiber reinforced materials, such as Aramid, Glass, and Carbon fiber, to replace the steel in the structural layer of flexible riser. Fiber reinforced materials show further elevated specific strength low density, excellent fatigue resistance, and corrosion resistance, and thus replacing traditional steel with carbon fiber is one of the solutions to solve the excessive weight and corrosion of flexible risers. During installation and operation, the riser may be subjected to axial compression and bending loads, as well as two potential mechanisms for stable failure of the pipe tensile armor:
- Radial buckling, also known as Birdcaging, which is usually occurred under axial compressive load.
- Lateral buckling, which is generally formed under cyclic bending load.
