US-based Stallion Oilfield Services has filed for Chapter 11 bankruptcy protection, hurt by a fall in the use of land-based drilling rigs and increased natural gas supply in the US.

In a filing with the US Bankruptcy Court for the District of Delaware, Stallion and 17 of its affiliates listed estimated assets and liabilities in the range of $500m to $1bn.

Stallion now has more than $80m of cash on hand to support its restructuring and operations, the company said in a statement.

Stallion said that secured lenders would receive about $25m in principal payments, reducing the company’s outstanding obligations under a secured credit agreement.

Stallion said that the number of land-based drilling rigs – a key indicator of the health of Stallion’s industry – has dropped precipitously from about 1,950 in September 2008 to less than 850 by June 2009, according to court documents.