Seadrill is an offshore drilling contractor providing worldwide offshore drilling services to the oil and gas industry. Its primary business is the ownership and operation of drillships, semi-submersible rigs, and jack-up rigs for operations in shallow to ultra-deep water in both benign and harsh environments. It provides a contract-based service and primarily serves the oil super-majors, integrated oil and gas, state-owned national oil, and independent oil and gas companies. Wikipedia