US proven oil reserves last year rose to their highest level since 1975, official figures have shown, in the latest sign of how the shale revolution has transformed the country’s energy supply outlook.
Proven reserves — oil that is expected to be recoverable with existing technology at current prices — were in decline in the US up until 2009, when companies began experiments with producing oil from the Bakken shale of North Dakota.
Rising reserves are an indication that higher US oil production, which has risen about 80 per cent since 2008, can be maintained in the longer term, although the recent slump in oil prices is expected to lead to cutbacks in activity and a slowdown in output growth over the coming months.