Investigation into float-over installations of minimal platforms by hydrodynamic model testing

The idea of using float-over installations for minimal facilities platforms was shown to offer significant advantages, especially when coupled with a substructure installed by a jackup rig. Recently, float-over installations of minimal facilities have been conducted by the cantilevered method by ICON Engineering PlY Ltd (ICON). The operation involves the platform topsides being loaded and transported to site on a barge, skidded over the barge bow, and lowered onto the jacket. The paper presents results of a research project undertaken by the Australian Maritime College (AMC) in conjunction with ICON, with the objective to investigate motions of a barge and loads exerted on the jacket when the two are docked together for a smooth load transfer operation. The model of an installation barge has been tested in the AMC wave basin and response amplitude operators of the barge motions have been determined for both the free floating and docked conditions. A range of wave periods and heights has beeninvestigated. Model test results have been used to verify numerical predictions used in the design, and to get insight into uncertainties, which may otherwise be difficult to assess using standard software.