Ensco plc is a prominent offshore drilling company with a history that began in 1975. Originally incorporated as Blocker Energy Corporation, it has grown through strategic acquisitions and investments to become a key player in the offshore oil drilling sector. The company specializes in offshore contract drilling services, operating a premium fleet that includes jackup rigs and ultra-deepwater semisubmersible rigs. Ensco is recognized for its advanced rig technology and commitment to safety and operational excellence.

In 2010, Ensco moved its global headquarters to London, reflecting its international presence. The company merged with Rowan Companies in 2019, forming EnscoRowan, which was later renamed Valaris. This merger created one of the largest offshore drilling fleets in the world, serving major oil and gas companies globally. Ensco's focus on premium rig management and engineering support has positioned it as a trusted partner in offshore oil exploration and production.