Research For Wall Thickness Design Of A Top Tensioned Riser For A Tensioned Leg Platform

Nowadays, platforms with riser system are widely used for marine oil industry. While steel catenary riser and top tensioned riser are two typical riser systems for use. Employment of TTR has been successful in shallow water. But the employment of TTR in deep water is not so mature.The main contents of this article: Based on key technologies of design for top tensioned riser and relative software development, research on the sub-project, the design and check of top tensioned riser(TTR)'s minimum wall thickness. With the basis of the preliminary design of a deep water TTR riser for a TLP platform, the riser's static strength is calculated and analyzed. And then a simplified design method is presented for calculating the riser's minimum wall thickness and the related mechanical behavior at the initial phase. Checking and analysis of key factors such as riser top tension and wall thickness, that affect the riser static performance, is done by using the simplified method, and then proposed optimization is given to the data obtained in the preliminary design.The first part of this article is to introduce problems and the development of their research of the field for deep water riser analysis. An introduction is made for the main direction of the work in this article. In the second part of this dissertation, the deep water riser mechanical model and its performance are introduced. The third part of this dissertation, introduced the analysis of the in-position strength of TTR with preliminary design data. And then calculate the influence that the riser setdown contribute to the top tension factor. With the usage of catenary equation, presents a simplified method for minimum wall thickness design and check. The fourth part of this dissertation, using the API RP 2RD code, presents the program based on the simplified method to check the riser's wall thickness by the combined stress and the hydrostatic pressure collapse and final the propagation collapse pressure. Part V using the Abaqus for static analysis of the TTR, and compared with the simplified method proposed in this paper. The results is compared and analyzed. Part VI is a summarize of the work of above, conclusion and the future outlook and opinions of the work.