Investors have viewed the barrel as half full lately when it came to the US oilfield services companies, bidding the sector up by 50 per cent since early March. A doubling in crude oil prices from their trough certainly is not bad news, but Halliburton chief David Lesar sounded a cautious tone on Monday for an important profit source: US natural gas. Its boom has busted spectacularly and the prognosis for a recovery in drilling activity looks bleak.

US gas storage is 2,860bn cubic feet, far above typical levels, and underlying consumption indicates tepid demand for these inventories once the heating season begins in three months. An ensuing collapse in prices has seen drilling activity scaled back sharply.