Chaparral Energy Inc. will not make an interest payment due April 1 tied to a $300 million bond, according to people familiar with the matter.

The privately-held E&P, which acquires and develops oil and natural gas properties in Oklahoma, Texas and Kansas, said in its annual report filed March 30 that it may seek Chapter 11 bankruptcy. It had missed a separate $16.5 million interest payment due March 1, kicking off a 30-day grace period.

A spokesperson for Chaparral did not respond to a request for comment. The sources asked not be identified because they were not authorized to speak to the media.

Should Chaparral file for bankruptcy, it would be joining about 40 other energy companies that sought court protection from their creditors last year as oil prices plunged.

Consulting firm Deloitte said that figure could balloon to 175 this year.

Chaparral lost $1.3 billion in the year ended Dec. 31, and has about $1.6 billion in debt, according to its annual report.

The company drew down the balance on its $548 million revolving line of credit in February. The lenders will redetermine the credit facility May 1, and Chaparral expects its borrowing base will be decreased significantly, it said in its annual report.

The company will then have to repay the outstanding balance within 30 days or in six monthly installments.

Chaparral's operations are focused on unconventional plays in the Midcontinent, including the Meramec, Oswego, Woodford, Mississippi Lime and Marmaton, according to the company's website.