Energy Supply: OIL and gas from the North Sea are instrumental in providing 70 per cent of the UK’s energy for transport, heating and electricity.

Production: Since UK production began, 40billion barrels of oil have been extracted from the seabed.

In 2009, the UK was the world’s 14th largest oil and gas producer, bigger than Qatar and Indonesia.

The UK industry pays a top tax rate of 75 per cent and has contributed more than £270billion to the Treasury.

Reserves: There are still up to 24billion barrels left to extract from the North Sea but these reserves are largely in remote locations and more difficult and expensive to extract than in the past.

Jobs: Around 440,000 jobs are supported by the UK industry, with about half in Scotland.

Exploration: Wells, costing between £10million and £40million, are drilled in the seabed to find out whether oil and gas are present.

To date, 11,000 wells have been drilled in UK waters including those for exploration, appraisal and production.

Platforms: There are currently 281 North Sea installations which either float or are fixed to the seabed on legs. About half of these are normally unmanned.

Pipelines: Once oil and gas has been extracted, it is transported ashore by tanker or a network of pipelines totalling 22,000 miles, double the distance from Aberdeen to Adelaide.

Offshore Shifts: Around 30,000 people work offshore in UK waters, typically for 10-and-a-half hours a day for two weeks, and then a helicopter returns them to shore where they have at least two weeks away from work.