Maintaining sufficient airgap between the wave crest and the bottom of deck steel in the wellbay area of column stabilized floating production units is one of the key design challenges for such structures and especially so in the harsh environments survival conditions.
In this paper, the effect of column configuration on the wave enhancement has been investigated. A detailed parametric study is performed to examine the influence of the column cross-sectional shape, column spacing relative to wavelength and column orientation relative to wave propagation direction on the wave enhancement. A four-column structure is considered in this parametric study. Platforms with circular and rectangular columns are investigated and compared. The results are calibrated with available model test results. For the selected configuration, time domain coupled analysis including first and second order wave elevation transfer functions are used.
A new column design with hybrid cross-sectional configuration is developed which significantly reduces the wave enhancement in the wellbay area. Numerical results are presented to illustrate the benefit from this new design.
The paper concludes with discussion on the constructability of the new configuration compared to the conventional design.