Floating drilling platform
First Claim
1. A floating semisubmersible off-shore drilling platform comprising a lower pontoon portion, an upper working portion, a plurality of columns supporting the working portion above the pontoon portion, said columns being exposed to the ambient water when the pontoon portion is submerged below the level of the water surface, a drill for drilling the sea bottom, said drill extending downwards in use from the working portion of the platform, and an ice shield surrounding the drill at the level of the pontoon portion to protect the drill from floating ice when the pontoon portion is at the level of the water surface.
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Accused Products
Abstract
A floating semisubmersible off-shore drilling platform or the like comprises an upper working level portion and a lower pontoon portion. When the platform is transported from one place to another, it floats on the pontoon portion, but when it is working as a stationary unit in open water, it is submerged deeper, so that the pontoon portion is at a considerable distance below the water surface and the working level portion is at a considerable distance above the water surface. The platform is adapted to withstand ice pressure from ice occurring in the ambient water by giving the pontoon portion of the platform a form particularly advantageous in ice conditions. When ice occurs, the platform is lifted to such a position, that its pontoon portion comes to float at the water surface level.
40 Citations
13 Claims
- 1. A floating semisubmersible off-shore drilling platform comprising a lower pontoon portion, an upper working portion, a plurality of columns supporting the working portion above the pontoon portion, said columns being exposed to the ambient water when the pontoon portion is submerged below the level of the water surface, a drill for drilling the sea bottom, said drill extending downwards in use from the working portion of the platform, and an ice shield surrounding the drill at the level of the pontoon portion to protect the drill from floating ice when the pontoon portion is at the level of the water surface.
- 10. A floating semisubmersible off-shore drilling platform comprising a lower pontoon portion, an upper working portion, a plurality of columns supporting the working portion above the pontoon portion, said columns being exposed to the ambient water when the pontoon portion is submerged below the level of the water surface, a drill for drilling the sea bottom, said drill extending downwards in use from the working portion of the platform, and an ice shield surrounding the drill at the level of the pontoon portion to protect the drill from floating ice when the pontoon portion is at the level of the water surface, the pontoon portion having a form paraticularly suited to ice conditions.
Specification