The Research On Hydrodynamic Performance Of New Type Of Extended Tension Leg Platform

With the development of offshore oil industry all over the world to more deep water, the exploration and development of deep water oil and gas has attracted more and more attention.For the development of offshore oil and gas engineering in our country is in a transition stage from shallow to deep, deep water oil and gas resources development of the south China sea is imminent. Motion performance of the traditional mobile platforms have already couldn’t satisfy the basic requirement of deep-water. With the increase of the depth of the water,the project cost of fixed platform and the weight of gravity platform increased significantly. Compared with other types of platform, tension leg platform(TLP) has large range of depth of application, and its sports performance and stability is also good, widely used and developmented in the world. So TLP has become one of the main form of deepwater production platform of the offshore oil industry.In view of the environmental conditions in the waters of the south China sea, extended tension leg platform(ETLP) has significant advantages in among the many structural type of tension leg platform.Firstly,this paper introduced the structure characteristics and the research situation of extended tension leg platform. Combined with the traditional type of extended tension leg platform,the new type of ETLP has inherited its advantages and revised its disadvantages.Through the integration design of pontoon and extension structure, the number of the platform module and welds has been reduced, and the platform construction period and construction costs has also been reduced.The reliability and safety of extension structure has been improved.Secondly, based on the three dimensional potential flow theory, this paper make a study of the new type ETLP in frequency domain dynamic characteristics by the combination method of theoretical analysis and numerical simulation.Using WADAM module in SESAM software, considering the additional stiffness of tension leg, calculate the natural period and the hydrodynamic parameters of the platform and motion response function of the platform in different directions of the wave loads, etc.By adjusting the dimensions of platform, improves its yaw performance.What’s more, explores that column spacing, tension leg stiffness, tension leg number how to influence the performance of new type of ETLP in frequency domain.Finally, considering the coupling relationship between variety of environmental load in South of China sea and platform motion, using DEEPC module in the SESAM software, establish numerical calculation model of the coupling motion system, and make calculation the motion response performance of the new platform under the loads of wind, wave and flow conditions and the nonlinear action of tension system in time domain.Then get the results of motion response of the new platform calendar, tensiknm tendon tension calendar and its extreme value, etc.Results show that the natural period of the new type of ETLP satisfied the specification requirements, at the same time the new type of ETLP has good hydrodynamic performance, and get the relationship between platform parameters like column spacing, tension leg stiffness, tension leg number and performance of new type of ETLP in frequency domain, which can provide certain reference for the research and development of TLP for deep sea area of the South sea of China.