Oil Rigs is a large structure that being used to house workers and machinery needed to drill wells for oil and gas.

There are some types of oil rig or platform such as below:

• Fixed platform.

This type of rigs are built on steel or concrete’s legs anchored directly onto the seabed, supporting a deck with space for drilling rigs, production facilities and crew quarters. Such building are, by virtue of their immobility, designed for very long term use. Various types of structure are used, steel jacket, concrete caisson etc. Steel jackets are vertical sections made of tubular steel members, and are usually piled into the seabed. Fixed platforms are economically feasible for installation in water depths up to about 1,700 feet (520 m).

• Compliant Towers

This oil rigs or platforms consist of slender flexible towers and of a pile foundation supporting a conventional deck for drilling and production operations. Compliant towers are designed to sustain significant lateral deflections and forces, and are typically used in water depths ranging from 1,500 to 3,000 ft (450 to 900 m).

• Semi Submersible Platform

This type of platform have hulls (columns and pontoons) of sufficient buoyancy to cause the structure to float, but of weight sufficient to keep the structure upright. Semi-submersible platforms can be moved from place to place; can be ballasted up or down by altering the amount of flooding in buoyancy tanks; they are generally anchored by combinations of chain, wire rope and/or polyester rope during drilling and/or production operations, though they can also be kept in place by the use of dynamic positioning. Semi-submersibles oil rigs can be used in water depths from 200 to 10,000 feet (60 to 3,050 m).

• Jack-Up Platforms

As the name, Jack-up building is a kind of platform that can be jacked up above the sea using his legs which can be lowered like jacks. These platforms are typically used in water depths up to 400 feet (120 m), and might be some design up to 170 meters. They are designed to move from place to place, and then anchor themselves by deploying the legs to the ocean bottom using a rack and pinion gear system on each legs.

• Drilling ships

A drillship oil rigs is a ship or vessel that has been fitted with drilling apparatus / equipment. It is most often used for exploratory drilling of new oil or gas wells in deep water but can also be used for scientific drilling. Drillships usually are prepared with a dynamic positioning system to maintain position over the well. They can drill in water depths up to 12,000 feet (3,660 m).

• Floating Production System

Floating production storage and offloading system (FPSO) and Floating Storage and offloading system (FSO) are the main types of floating production systems. FPSOs are large ships equipped with processing facilities and moored to a location for extended periods, and do not actually drill for oil or gas

Spar Platform

This type of oil rigs (Spars) is moored to the seabed like the TLP, but whereas the TLP has vertical tension tethers, the Spar has more conventional mooring lines. The Spar may be more economical to build for small and medium sized rigs than the TLP, and has more inherent stability than a TLP since it has a large counterweight at the bottom and does not depend on the mooring to hold it upright. It also has the ability, by use of chain-jacks attached to the mooring lines, to move horizontally over the oil field.

• Tension Leg Platform.

TLPs is a floating platforms tied to the seabed in a manner that eliminates most vertical movement of the structure. TLPs is used in water depths up to about 6,000 feet (2,000 m).