The Overall Reponse Characteristics Research And Fatigue Analysis Of The Lazy-wave Flexible Riser

In recent years, the exploration of the resource in ocean is more and more，especially the exploration and production of the oil and gas. Now, the exploration andproduction activity is gradually transferring to the deep water from the shallow water.Many production systems are builded with the increasing of the depth of water. It isalso true for China offshore industry. Recent exploration activities indicate thediscovery of hydro carbon resources in the South China Sea.Regardless of the floater concept adopted for offshore field development, there isalways a need of risers, which form the critical parts of offshore infrastructure. In theriser system,the flexible Risers are used widely in the deepwater oil and gasproduction. The assignment of this thesis is to carry out the configuration design andanalysis work of a flexible riser, including the static and dynamic characteristics underdifferent shapes, the analysis of riser strength and the analysis of motion fatigue.1. The static and dynamic characteristics of the free-hang catenary flexible riserand lazy-wave flexible riser were studied by the theory method and the OrcaFlex. Thesensitivity analyses of the main parameters were also carried out;2. Static and dynamic strength analysis of the riser was finished using theOrcaFlex software;3. Dynamic response of riser was achieved using OrcaFlex software. Then thelocal finite element model was built by the Bflex. Finally the motion fatigue life wasobtained by the model；4. Finished the real scale fatigue test equipment design for the flexible riser, anduse the software Bflex to simulate the device to verify the correctness of the device.