Research On The Mooring Design Of CALM System Of FPSO

As the abbreviation shows, the FPSO (Floating Production Storage and Offloading system) system has the functions of Floating Production, Storage, and Offloading. and it includes process equipment, ship system and mooring system. Because FPSO system has many features, such as Adaptability for water depth., powerful resistance to wind ,wave and current, little investment and fast return, Movable and relocatable, and lower risky, it's widely applied to offshore oilfield developments. It becomes one of the three main equipments of ocean oil development,and have make a great contribution to the World Oil Industry.FPSO system often works in a fixed region, so it calls higher requirements for its mooring system. Because of this, the mooring system design has been always a key technology. Currently FPSO's mooring system are mainly the SPM(Single Point Mooring)system. This paper has summed up the characteristics of the SPM system and its advantages compared with other mooring systems. Then focuses on the preliminary design of the CALM (Catenary Anchor Leg Mooring) system, which accounts for over half of the total number of the SPM system. On the basis of certain assumptions and the Catenary theory , the single component mooring system and the two components mooring system have been conducted a static analysis respectively. For the single component mooring system, the paper has conducted a series of computations with several frequently-used materials. Then we can gain a collection of graphs, which are unrelated to the concrete mooring float, the area and the environment conditions, and it's to say that they have universal property. These graphs can help designers choose the proper material of mooring line and mooring equipments. For two component mooring system, there are combinations of the breaking load, materials prices and the length of each components. This raises the combinatorial optimization problem of all constituents. Inspired by the work of predecessors, the author uses single and objectives optimization methods respectively, analyzes and compared with the two results, and draws relevant conclusions.Through this work, the authors have a more profound understanding of the concept of a single-point mooring system, especially the quasi-static analysis methods of the preliminary design phase and the physical model of floats -mooring line system, and have an initial understanding of the combinatorial optimization problems of the multi-components mooring lines.The methods and the conclusions of this paper have some reference value and engineering practical significance to the study and the preliminary design of the CALM system.