April's running tally for U.S.-based energy defaults has reached $14 billion so far, according to Fitch ratings.
This week, oil and gas exploration firm Energy XXI and coal giant Peabody Energy both filed for bankruptcy while Linn Energy missed a debt payment.
And today, Houston-based Goodrich Petroleum has announced it has filed for voluntary restructuring under Chapter 11, as the firm looks to cut around $400 million debt from its balance sheet.
The U.S. shale revolution of the last few years has been typically backed by small and mid-sized firms who borrowed heavily to finance operations.
"The biggest cost for U.S. shale oil is digging wells. In order to keep in business firms will have to return to the debt market to raise cash.
"This is where the problem lies, if you lent to them at $100 per barrel a few years ago you will think twice about lending to them at sub $50," said Alex Dryden, analyst at J.P. Morgan Asset Management Friday.