The world’s largest oilfield services firms are finally seeing a return to profit. 1H 2017 is the first time Schlumberger, Halliburton and Baker Hughes have made a combined half-yearly profit since the first half of 2015.

Following the aftermath of the oil price collapse the big three oilfield services firms became more dependent on revenue from the Middle East – the only global region to increase upstream spending last year. But North America, and US shale in particular,...