The US alone accounted for more than half of active rigs in 2014 worldwide, according to oilfield services company Baker Hughes, which provides estimates of numbers of drilling rigs in use.
Its frenetic level of drilling activity helps the US punch way above its weight in production: even though it owns just 3% of global reserves, the US produces more oil than any other country apart from Saudi Arabia and Russia. At present, it accounts for more than a tenth of global oil production, and could soon regain its long-lost mantle as the world’s biggest oil producer.
America’s high rig count is partly down to things like its entrepreneurial culture and petroleum-based economy, and a well-oiled services industry. But it’s mainly because unconventional oil production – the reason for virtually all of the astonishing growth in US oil production in recent years – needs a high number of wells. According to the International Energy Agency, maintaining production at 1 million barrels a day in North Dakota’s Bakken shale requires 2,500 new wells a year; a large conventional field in southern Iraq needs just 60.