Stability Studies on Offshore Triceratops

Abstract

In the present days the oil exploration is going to deeper and ultra deep water depths. Deep and ultra deep water structures needs special care to reduce the motion responses. Triceratops (introduced by Charles et al. (2005)) is a new generation of the offshore structure with three Buoyant Leg Structures (BLS), deck, ball joints between the BLS and the deck and the foundation system either with restraining leg or with tethers. Triceratops can be installed by free floating each BLS followed with deck mating. For these purposes, the present paper discusses the hydrostatics of BLS's with two different mass distributions. The heave, roll, and pitch free oscillation studies are conducted for BLS and Triceratops experimentally and analytically. The free floating natural periods in roll and pitch degrees of freedom are found away from the wave periods which shows the ease in installation and decommission.