Some Aspects of Spar Platform Buoyancy Can Loads

A finite element program is developed to analyze the dynamics of buoyancy cans within the centerwell of Spar platforms. The time domain non-linear finite element model includes the effects of the hydrodynamics of the water within the centerwell, and, the gap between the buoyancy cans and guides. The forces on the buoyancy can guide structure due to Spar motions is studied in the present paper. The theoretical results are validated with experimental and field measurements. 1:20.89 scale model tests are conducted to measure the buoyancy can motions and guide reaction forces for a range of gap sizes and specified Spar motions. A Spar platform is also instrumented to measure the guide forces in actual field conditions. The prototype field data is analyzed and compared with the numerical predictions.