Oil prices fell to their lowest point in 11 years Wednesday, continuing a plunge that has hit U.S. exploration and production companies hard.

At least nine oil and gas companies accounting for more than $2 billion in debt filed for bankruptcy in the fourth quarter, according to OilPrice.com, and falling energy prices have contributed to the collapse of at least one notable law firm, Texas-based energy boutique Burleson. Other firms with major energy practices have laid off lawyers and staffers.

Firms with robust restructuring practices, on the other hand, are making the best of the energy industry's woes. Chapter 11 filings have bottomed out after the Great Recession, but the last few weeks of 2015 and early days of 2016 saw several new assignments come across the desks of Am Law 100 firms.