Nonlinear hydrodynamic characteristics of multi-body platform system

Along with the technology development of ocean resources, offshore platforms are gradually becoming larger and more complex. Recent development of the oil and gas field in the deep-water region often involves multiple floating platforms adjacent to each other to perform more complex functions for oil and gas production. This paper describes the investigation carried out on the dynamic responses of a two platforms system containing a Tension Leg Platform (TLP) and a tender assisted drilling (TAD) with a flexible connection between the two platforms. The mooring lines and tendons are taken into consideration in the coupled analysis of the multi-body platform's system. The motion responses and wave load characteristics on the two platforms in multi-body coupled model are investigated in the numerical simulation. Compared to the situation of the two platforms in isolation, it is revealed that the motion responses for the two platforms in coupled model are altered by the combined effects of the platforms' interaction and constrain by the connection. The interaction between platforms can increase both the first- and second-order wave force on platforms in the arrangement direction of two platforms. Quantitative analysis demonstrates their relative importance and thus provides much-needed guidance in practical design of the coupled system.