US exploration and production companies have raised more from bond sales in 2017 than in any year since the slump in oil prices began in 2014, shoring up their finances to support drilling and production growth. Equity financing for the US E&P industry, which boomed in 2016, has slumped this year, but the debt market has been robust, accounting for the largest share of oil and gas E&P company fundraisings since 2009.

Companies in the sector have raised just under $60bn in bond sales so far this year, already a 28 per cent jump from 2016, according to Dealogic. Over the past three weeks, Whiting Petroleum, Continental Resources and Endeavor Energy Resources have each raised $1bn in debt. The bond sales have helped finance increased activity in US shale reserves. The number of rigs drilling the horizontal wells used for shale oil production has more than doubled from its low of 248 in May last year to 652 last week, according to Baker Hughes, the oilfield services group controlled by General Electric. “It is the resurgence in the commodity, that’s the bottom line,” said Tom Stolberg, a portfolio manager with Loomis Sayles.

“The commodity trending better has brought out a slew of new issuance. The fringier [companies], lower rated, more stressed balance sheets, it benefits them a whole lot more because it gets them over the hump of not making it at $50 or $45 oil.”