White Deer Energy, a private equity firm focused on energy, has acquired RockPile Energy Services LLC for an undisclosed amount, RockPile said Sept. 8.

Denver-based RockPile is a subsidiary of Triangle Petroleum Corp. (NYSE: TPLM), which filed for chapter 11 in June. The company provides completions services primarily in the Williston and Permian basins.

RockPile will move forward with a debt-free balance sheet and adequate capital to fund growth, according to a press release. In addition, RockPile's management team will remain intact.

The transaction was concluded on an out of court basis and involved no form of bankruptcy for the company or subsidiaries, the release said.

PJT Partners and AlixPartners were financial advisers to RockPile. Skadden, Arps, Slate, Meagher & Flom was the company's legal adviser. Locke Lord was legal adviser to White Deer Energy.

White Deer Energy has $2.2 billion of capital commitments across two private equity funds, the release said. The firm has offices in Houston and New York.