China is on track to produce enough crude oil outside its borders to rival Opec members such as Kuwait and the United Arab Emirates, after its state-owned oil companies spent a record $35bn buying foreign rivals last year.

In the first tally of the impact of China’s recent overseas oil investments, the International Energy Agency calculates China’s national oil companies will produce 3m barrels a day abroad in 2015, double their 2011 overseas output of 1.5m b/d and equivalent to Kuwait’s annual production.

“China is set to become a major producing country outside of its borders,” Fatih Birol, chief economist at the IEA, told the Financial Times on the sidelines of IP Week, an annual gathering of the oil industry in London. “A significant part of the increased foreign production comes from [merger and acquisition] transactions last year.”