Wikipedia
Patterson-UTI
Formed in 1979 as Patterson Drilling and 1986 as UTI Energy (to purchase Universal Well Services, Union Supply Company, Triad Drilling Company, and International Petroleum Services Company from UGI Corp) , Patterson-UTI Energy operates land-based drilling rigs in the United States and Canada. The company comprises three segments: Contract Drilling, Pressure Pumping, and Oil and Natural Gas. It is a constituent of the S&P 400.