Tesco Corporation (Tesco) is an oilfield services company specializing in the design, manufacture and service of technology-based solutions for the upstream energy industry. Its headquarters are located in the Spring Branch district of Houston, Texas, United States. Tesco was created in December 1993 when Shelter Oil and Gas Ltd., Coexco Petroleum Inc., and Forewest Industries Ltd. merged as Tesco Corporation, originally Tesco Drilling Technology, a joint venture between the three. Tesco originally became famous for inventing the first portable land top drive, which won a Special Meritorious Award for Engineering at the 1994 OTC show. Since then, Tesco has branched out into casing running as well, including a casing running tool called the Casing Drive System, or CDS. In 2006, the company moved their headquarters from Calgary, AB to Houston, TX, while continuing to manufacture in Calgary. On 30 April 2012, Tesco and Schlumberger announced a deal in which Tescos CASING DRILLING™ division would be sold to Schlumberger for $45 million in cash.