Allis-Chalmers Energy Inc. provides services and equipment to oil and natural gas exploration and production companies in the United States. It operates through three segments: Oilfield Services, Drilling and Completion, and Rental Services. The Oilfield Services segment provides well planning and engineering services, directional drilling packages, downhole motor technology, well site directional supervision, exploratory and development re-entry drilling, downhole guidance services, and measurement-while-drilling services. It also offers compressed air equipment, chemicals, and other specialized products for underbalanced drilling and production applications; specialized equipment and trained operators to perform various pipe handling services; and production-related rental tools and equipment and services, including wire line support services and coiled tubing. The Drilling and Completion segment provides drilling, completion, workover, and related services for oil and natural gas wells. It also offers various other oilfield services, such as drilling fluids and completion fluids; engineering and logistics; and rigs and drilling crews, and rig management services. The Rental Services segment provides specialized oilfield rental equipment, including premium drill pipes, spiral heavy weight drill pipes, tubing work strings, blow out preventers, choke manifolds, and various valves and handling tools for onshore and offshore well drilling, completion, and workover operations, as well as double studded adapters, test plugs, wear bushings, adaptor spools, baskets, spacer spools, and other assorted handling tools. The company offers its products in Texas, Louisiana, Pennsylvania, West Virginia, Wyoming, Oklahoma, and offshore in the Gulf of Mexico, as well as in Argentina, Brazil, Bolivia, and Mexico. Allis-Chalmers Energy Inc. was founded in 1913 and is based in Houston, Texas. Allis-Chalmers Energy Inc. operates as a subsidiary of Archer Limited.