An oil platform, also referred to as an offshore platform or, somewhat incorrectly, oil rig, is a lаrge structure with facilities to drill wells, to extract and process oil

Petroleum

Petroleum or crude oil is a naturally occurring, flammable liquid consisting of a complex mixture of hydrocarbons of various molecular weights and other liquid organic compounds, that are found in geologic formations beneath the Earth's surface. Petroleum is recovered mostly through oil drilling...

 and natural gas

Natural gas

Natural gas is a naturally occurring gas mixture consisting primarily of methane, typically with 0–20% higher hydrocarbons . It is found associated with other hydrocarbon fuel, in coal beds, as methane clathrates, and is an important fuel source and a major feedstock for fertilizers.Most natural...

, and to temporarily store product until it can be brought to shore for refining and marketing. In many cases, the platform contains facilities to house the workforce as well.

Depending on the circumstances, the platform may be fixed

Fixed Platform

A fixed platform is a type of offshore platform used for the production of oil or gas. These platforms are built on concrete and/or steel legs anchored directly onto the seabed, supporting a deck with space for drilling rigs, production facilities and crew quarters. Such platforms are, by virtue of...

 to the ocean floor, may consist of an artificial island

Artificial island

An artificial island or man-made island is an island or archipelago that has been constructed by people rather than formed by natural means...

, or may float.

Remote subsea

Subsea

Subsea is a general term frequently used to refer to equipment, technology, and methods employed in marine biology, undersea geology, offshore oil and gas developments, underwater mining, and offshore wind power industries.- Oil and gas :...

 wells may also be connected to a platform by flow lines and by umbilical

Umbilical cable

An umbilical cable or umbilical is a cable which supplies required consumables to an apparatus. It is named by analogy with an umbilical cord...

 connections; these subsea solutions may consist of single wells or of a manifold centre for multiple wells.
Around 1891 the first submerged oil wells were drilled from platforms built on piles in the fresh waters of the Grand Lake St. Marys

Grand Lake St. Marys

Grand Lake Saint Marys State Park is an Ohio state park, west of St. Marys, and south-east of Celina, south-west of Lima in the north-western part of the U.S. state of Ohio.Grand Lake covers in Mercer and Auglaize counties...

 (a.k.a.