What is Drilling Oil Rig?

A drilling rig is a structure housing equipment used to drill for water, oil, natural gas from underground reservoirs or to obtain mineral core samples. The term can refer to a land-based rig, a marine-based structure commonly called an 'offshore rig' or a structure that drills oil wells called an 'oil rig'. The term correctly refers to the equipment that drills oil wells or extracts mineral samples, including the rig derrick (which looks like a metal frame tower).

Sometimes a drilling rig is also used to complete (prepare for production) an oil well. However, the rig itself is not involved with the extraction of the oil, its primary function is to make a hole in the ground so that the oil can be produced.

Laypeople may refer to the structure which sits on top offshore wells as a 'rig', but this is not correct. The correct name for the structure in a marine environment is platform. A structure upon which wells produce is a production platform. A floating vessel upon which a drilling rig sits is a floating rig or semi-submersible rig because the whole purpose of the structure is for drilling.

Drilling rigs can be small and portable such as those used in mineral exploration drilling, or huge, capable of drilling through thousands ofmetres of the Earth's crust; large "mud pumps" are used to circulate drilling mud (slurry) through the drill bit and the casing, for cooling and removing the "cuttings" whilst a well is drilled; hoists in the rig can lift thousands of tons of pipe; other equipment can force acid or sand into reservoirs to facilitate extraction of the oil or mineral sample; and permanent living accommodation and catering for crews which may be greater than a hundred people in number. Marine rigs may operate many hundreds of miles or kilometres offshore with infrequent crew rotation.

Source: Wikipedia