They are the set up structures in the marine or sea environment for the purpose of Transmission and production such as electricity, energy, telecommunication, oil and gas.
Offshore and marine platforms provide a surface to carry out operations as those undertaken onshore, drilling wells and producing from them and processing, storing and exporting oil and gas using similar equipment processes and techniques to those deployed onshore.
Several designs exist for the substructure of offshore and marine platforms. The choice depends on the functions the unit will perform and on the conditons it will experience.
Exploration wells are oftend drilled by mobile offshore drilling units or mode which is a generic term for various types of floating or floatable drilling machines. In very shallow waters or in lakes and rivers drilling can be performed from a flat bottom barge or from a submersible buoyancy tanks, are flooded with water until the unit rests on the sea floor. After drilling, the water is pumped out and the vessel can be refloated and towed to a new location.
Jack up rigs used in shallow waters of up to around 120 meters have three or four large latticed legs. The rig is towed to the site with its legs, up the legs are then lowered to the sea floor and the top sides are jacked up so that they rest above the water. When drilling is finished, the legs are raised and the platform can be towed to the next site.