Nonlinear time-domain simulations are performed to analyze various floatover installation scenarios, including docking, mating, and undocking operations at different critical stages. Their findings are used to properly define the limiting environmental conditions, the dynamic behavior of the floatover barge, the movement of stabbing cones, as well as guide the design of LMUs, DSUs, and fender system, etc. This paper takes the 8,700Te integrated topsides of BZ34-1 CPP Platform as an example and presents the nonlinear time-domain mating analysis and its application to a typical floatover installation design in the shallow water and benign environment of Bohai Bay, China.
Floatover technologies have been gaining more and more popularity in recent years, particularly in the shallow water and benign environment, such as Bohai Bay, China. Since 2002 there have been eleven successful floatover installations performed in the Bohai Bay using conventional floatover method and strand jack lifting scheme, and many more floatover installations will follow thereafter. The floatover technology uses varied functions of floatover systems and lets large platform topsides be installed as a single integrated package without the use of a heavy lift crane vessel. This allows not only elimination of expensive day-rate derrick barges, minimization of offshore hookup, and maximization of onshore testing and commissioning, but also freedom of equipment layout within the deck compared to modular lifting designs. Nonlinear time-domain simulations are performed to analyze various installation scenarios including docking, mating, and undocking operations at different critical stages, thus defining the limiting environmental conditions, the dynamic behavior of the floatover barge and the movement of stabbing cones. The limiting environmental conditions and the dynamic behavior of the barge defined by the mating analysis shall be monitored via an environmental measure system and a motion monitoring system, respectively, during floatover operations.