Research On Analysis Design Of Basic Torsion Performance Of Umbilical Cable In Subsea Production System

Umbilical cable is an important industrial equipment for marine oil and gas development.It has the function of connecting underwater production systems and sea surface control systems to provide power,hydraulic power,chemical agents and data signal which is necessary for normal operation of underwater production systems.The nature of the cable is a composite pipeline consisting of pipes,cables,optical-cables and fillers.The overall structure is a typical non-adhesive,slip-able helically wound structure,which is very complicated.Umbilical cable in the storage,installation,operation and other conditions will be subject to tension,bending,twisting and other combined load,so high mechanical properties are required.the marine engineering equipment started late in China.Umbilical cables used in the oil field and other important equipment heavily rely on imports,which restricts China's energy security.In this paper,according to the design of umbilical cable,the different loads under different working conditions are analyzed in the paper.The basic failure modes are defined,and the structural analysis and design of the umbilical cable under different failure modes are summarized.At the same time,the analysis model of the umbilical cable is established by using the elastic mechanics method with consideration of the radial deformation.and the stiffness matrix of the structure under the torsional load is obtained.Deep-water umbilical cable generally has two layers and even more layers of armored structure.the torsion unbalance problem will exist when this structure be twisted.refer to the study of the torsion equilibrium,an index and method for evaluating and designing the torsion balance performance are put forward.Taking into account the radial deformation of the structure,a simplified form of the method is also given.In this paper,the study focuses on the torsion performance of the umbilical.the specific design and design methods two most important indicators are presented,which are conducive to structure design of the umbilical cable for China Offshore oil and gas development and provide technical reserves.