Patterson-UTI Energy, Inc., through its subsidiaries, provides onshore contract drilling services to major and independent oil and natural gas operators in the United States and Canada. The company offers pressure pumping services that consist of well stimulation and cementing for completion of new wells and remedial work on existing wells, as well as hydraulic fracturing, nitrogen, cementing, and acid pumping services in Texas and the Appalachian Basin; and contract drilling services primarily in Texas, New Mexico, Louisiana, Arkansas, Oklahoma, Colorado, Utah, Wyoming, Montana, North Dakota, Nebraska, Alaska, Kansas, Pennsylvania, Ohio, West Virginia, Michigan, and western and northern Canada. It also owns and invests in oil and natural gas assets located primarily in Texas and New Mexico. As of December 31, 2012, it had a drilling fleet of 314 marketable land-based drilling rigs. Patterson-UTI Energy, Inc. was founded in 1978 and is headquartered in Houston, Texas.