These platforms are used either for drilling wells or as support for production wells or for both. There are several types and the choice is made based on usage, environmental conditions.
Offshore platforms may be broadly classified into two types.
- Platforms Resting on Sea bottom
− Piled Platforms: All steel towers fall under this category. These platforms are essentially made of steel tubular members fabricated on a dock wall, transported by means of launch barge, launched at locations ,upended and fixed to the sea bottom by driving steel pipe piles through the legs. These are also called jacket platforms or template platforms.
− Gravity Platforms : These platforms rest on the sea bottom and resist external forces due to winds waves etc. through friction between the platform bottom and sea bed . These platforms are very massive and depend for their stability on the weight of the platform.
− Jack up rigs : Self elevating platforms or Jack up platforms have a platform hull structure which floats and also movable legs which floats , which are lowered at the required location with the help of pneumatic or hydraulic jacks or electric racks and pinion drives.
- Floating Platforms
− Semi submersibles : Semi –submersible platform are usually moored in position with elaborate system of anchors, chain and tension devices for water depths up to 460m and designed that the buoyancy chamber is well below the water surface so that the effect of wave forces is minimum.
− Ship type platforms : Ship type platforms are designed mainly for operation in deep water and for use drilling in depths of 200m and more. They are used because of their very good mobility and higher carrying capacity.
These platforms are used either for drilling wells or as support for production wells or for both. There are several types and the choice is made based on usage, environmental conditions.
Offshore platforms may be broadly classified into two types.
- Platforms Resting on Sea bottom
− Piled Platforms: All steel towers fall under this category. These platforms are essentially made of steel tubular members fabricated on a dock wall, transported by means of launch barge, launched at locations ,upended and fixed to the sea bottom by driving steel pipe piles through the legs. These are also called jacket platforms or template platforms.
− Gravity Platforms : These platforms rest on the sea bottom and resist external forces due to winds waves etc. through friction between the platform bottom and sea bed . These platforms are very massive and depend for their stability on the weight of the platform.
− Jack up rigs : Self elevating platforms or Jack up platforms have a platform hull structure which floats and also movable legs which floats , which are lowered at the required location with the help of pneumatic or hydraulic jacks or electric racks and pinion drives.
- Floating Platforms
− Semi submersibles : Semi –submersible platform are usually moored in position with elaborate system of anchors, chain and tension devices for water depths up to 460m and designed that the buoyancy chamber is well below the water surface so that the effect of wave forces is minimum.
− Ship type platforms : Ship type platforms are designed mainly for operation in deep water and for use drilling in depths of 200m and more. They are used because of their very good mobility and higher carrying capacity.