Ensco Offshore Company, located in Houston, Texas, is a private subsidiary of the United Kingdom-based Ensco plc. The parent firm is one of the leading providers of offshore contract drilling services to the major international, government-owned and independent oil and gas companies. It employs more than 3,700 people. The company owns and operates a fleet of approximately 45 drilling rigs, including 40 jack-up rigs, four ultra-deepwater semi-submersibles and a barge, located in some of the most prolific oil and gas markets around the world. Four major business units, including Deepwater, Asia-Pacific Rim, Europe-Africa, and North and South America manage Ensco plc s fleets.