Business	6 Months Ended
Jun. 30, 2017
Business
Business	Note 1—Business Transocean Ltd. (together with its subsidiaries and predecessors, unless the context requires otherwise, “Transocean,” “we,” “us” or “our”) is a leading international provider of offshore contract drilling services for oil and gas wells. We specialize in technically demanding sectors of the offshore drilling business with a particular focus on deepwater and harsh environment drilling services. Our mobile offshore drilling fleet is considered one of the most versatile fleets in the world. We contract our drilling rigs, related equipment and work crews predominantly on a dayrate basis to drill oil and gas wells. At June 30, 2017, we owned or had partial ownership interests in and operated 44 mobile offshore drilling units, including 30 ultra‑deepwater floaters, seven harsh environment floaters, three deepwater floaters and four midwater floaters. At June 30, 2017, we also had four ultra‑deepwater drillships under construction or under contract to be constructed. On May 31, 2017, we completed the sale of 10 high‑specification jackups and novated the contracts relating to the construction of five high‑specification jackups, together with related assets. At June 30, 2017 we operated two high‑specification jackups that were under contract when we sold the rigs, and we continue to operate such rigs until completion or novation of the drilling contracts (see Note 5—Drilling Fleet).

Business

6 Months Ended

Jun. 30, 2017

Note 1—Business

Transocean Ltd. (together with its subsidiaries and predecessors, unless the context requires otherwise, “Transocean,” “we,” “us” or “our”) is a leading international provider of offshore contract drilling services for oil and gas wells. We specialize in technically demanding sectors of the offshore drilling business with a particular focus on deepwater and harsh environment drilling services. Our mobile offshore drilling fleet is considered one of the most versatile fleets in the world. We contract our drilling rigs, related equipment and work crews predominantly on a dayrate basis to drill oil and gas wells. At June 30, 2017, we owned or had partial ownership interests in and operated 44 mobile offshore drilling units, including 30 ultra‑deepwater floaters, seven harsh environment floaters, three deepwater floaters and four midwater floaters. At June 30, 2017, we also had four ultra‑deepwater drillships under construction or under contract to be constructed.

On May 31, 2017, we completed the sale of 10 high‑specification jackups and novated the contracts relating to the construction of five high‑specification jackups, together with related assets. At June 30, 2017 we operated two high‑specification jackups that were under contract when we sold the rigs, and we continue to operate such rigs until completion or novation of the drilling contracts (see Note 5—Drilling Fleet).