Inventors:
Brian J. Watt - Kingwood TX
Dilipkumar N. Bhula - Houston TX
Jal N. Birdy - Kingwood TX
Assignee:
Chevron Research Company - San Francisco CA
International Classification:
E02B 1702
Abstract:
The Removable Bottom Founded Structure (RBFS) is an offshore platform for petroleum drilling and producing operations intended for deployment in waters with severe weather and iceberg conditions. The structure is normally held down by gravity, but during the deballasting procedure a hold-down system is employed to keep the platform on the subbase until site evacuation. The system that is used to hold the platform down onto the subbase is located where the platform meets the subbase. It operates on the principle of hydrostatics. On the underside of the columns there are elastomeric seals that define chambers between the column and the subbase which may be evacuated by pumping. Pressure by the platform weight forces the elastomeric seals down onto the subbase to create a fluid-tight seal so that no seawater will enter the evacuated chambers. The reduction of the buoyancy forces will hold the platform onto the subbase until such time as the platform is totally deballasted. Once that has occurred, the hydrostatic hold-down system is disengaged and the platform will quickly rise to the surface.