Britain has substantial oil and gas reserves offshore on the United Kingdom Continental Shelf (UKCS). Before the 1970s it was almost wholly dependent on imports for oil supplies.
Around 34,000 people are employed offshore, while a further 250,000 work in support industries - building oil rigs, designing platforms and pipelines, operating helicopters and boats and so on. Gross capital investment from British sources in oil and gas extraction represents about 20 per cent of British industrial investment.
Output of crude oil and natural gas liquids in Britain average just over 2 million barrels (around 274,000 tonnes) a day in 1993, making Britain the world's tenth largest oil producer.