Nature of Business	12 Months Ended
Dec. 31, 2013
Nature of Business
Nature of Business	Note 1—Nature of Business Transocean Ltd. (together with its subsidiaries and predecessors, unless the context requires otherwise, “Transocean,” the “Company,” “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 December 31, 2013, we owned or had partial ownership interests in and operated 79 mobile offshore drilling units associated with our continuing operations. At December 31, 2013, our fleet consisted of 46 High-Specification Floaters (Ultra-Deepwater, Deepwater and Harsh Environment semisubmersibles and drillships), 22 Midwater Floaters, and 11 High-Specification Jackups. At December 31, 2013, we also had seven Ultra-Deepwater drillships and five High-Specification Jackups under construction or under contract to be constructed. See Note 10—Drilling Fleet. We also provide oil and gas drilling management services, drilling engineering and drilling project management services primarily in the North Sea, through Advanced Drilling Technology International Limited (“ADTI”), our wholly-owned United Kingdom (“U.K.”) subsidiary. ADTI conducts drilling management services primarily either on a dayrate or on a completed-project, fixed-price or turnkey basis. See Note 27—Subsequent Events. In November 2012, in connection with our plan to discontinue operations associated with the standard jackup and swamp barge asset groups, we completed the sale of 37 standard jackups and one swamp barge to Shelf Drilling Holdings, Ltd. (“Shelf Drilling”). For a transition period following the completion of the sale transactions, we agreed to continue to operate a substantial portion of the standard jackups on behalf of Shelf Drilling and to provide certain other transition services to Shelf Drilling. Under operating agreements, we agreed to continue to operate these standard jackups on behalf of Shelf Drilling for periods ranging from nine months to 27 months, until expiration or novation of the underlying drilling contracts by Shelf Drilling. Under a transition services agreement, we agreed to provide certain transition services for a period of up to 18 months following the completion of the sale transactions. As of December 31, 2013, we operated seven standard jackups under operating agreements with Shelf Drilling. See Note 7—Discontinued Operations. In March 2012, we announced our intent to discontinue drilling management operations in the shallow waters of the U.S. Gulf of Mexico, upon completion of our then existing contracts. In December 2012, we completed the final project of our drilling management services operations in the U.S. Gulf of Mexico and discontinued offering our drilling management services in this region. See Note 7—Discontinued Operations. In March 2011, we committed to a plan to sell the assets and discontinue the operations of our oil and gas properties operating segment, which comprised the exploration, development and production activities performed by Challenger Minerals Inc., Challenger Minerals (North Sea) Limited and Challenger Minerals (Ghana) Limited (collectively, “CMI”). In October 2011, we completed the sale of Challenger Minerals (North Sea) Limited, in April 2012, we completed the sale of the assets of Challenger Minerals Inc. and, in December 2012, we completed the sale of the assets of Challenger Minerals (Ghana) Limited. See Note 7—Discontinued Operations.

Note 1—Nature of Business

Transocean Ltd. (together with its subsidiaries and predecessors, unless the context requires otherwise, “Transocean,” the “Company,” “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 December 31, 2013, we owned or had partial ownership interests in and operated 79 mobile offshore drilling units associated with our continuing operations. At December 31, 2013, our fleet consisted of 46 High-Specification Floaters (Ultra-Deepwater, Deepwater and Harsh Environment semisubmersibles and drillships), 22 Midwater Floaters, and 11 High-Specification Jackups. At December 31, 2013, we also had seven Ultra-Deepwater drillships and five High-Specification Jackups under construction or under contract to be constructed. See Note 10—Drilling Fleet.

We also provide oil and gas drilling management services, drilling engineering and drilling project management services primarily in the North Sea, through Advanced Drilling Technology International Limited (“ADTI”), our wholly-owned United Kingdom (“U.K.”) subsidiary. ADTI conducts drilling management services primarily either on a dayrate or on a completed-project, fixed-price or turnkey basis. See Note 27—Subsequent Events.

In November 2012, in connection with our plan to discontinue operations associated with the standard jackup and swamp barge asset groups, we completed the sale of 37 standard jackups and one swamp barge to Shelf Drilling Holdings, Ltd. (“Shelf Drilling”). For a transition period following the completion of the sale transactions, we agreed to continue to operate a substantial portion of the standard jackups on behalf of Shelf Drilling and to provide certain other transition services to Shelf Drilling. Under operating agreements, we agreed to continue to operate these standard jackups on behalf of Shelf Drilling for periods ranging from nine months to 27 months, until expiration or novation of the underlying drilling contracts by Shelf Drilling. Under a transition services agreement, we agreed to provide certain transition services for a period of up to 18 months following the completion of the sale transactions. As of December 31, 2013, we operated seven standard jackups under operating agreements with Shelf Drilling. See Note 7—Discontinued Operations.

In March 2012, we announced our intent to discontinue drilling management operations in the shallow waters of the U.S. Gulf of Mexico, upon completion of our then existing contracts. In December 2012, we completed the final project of our drilling management services operations in the U.S. Gulf of Mexico and discontinued offering our drilling management services in this region. See Note 7—Discontinued Operations.

In March 2011, we committed to a plan to sell the assets and discontinue the operations of our oil and gas properties operating segment, which comprised the exploration, development and production activities performed by Challenger Minerals Inc., Challenger Minerals (North Sea) Limited and Challenger Minerals (Ghana) Limited (collectively, “CMI”). In October 2011, we completed the sale of Challenger Minerals (North Sea) Limited, in April 2012, we completed the sale of the assets of Challenger Minerals Inc. and, in December 2012, we completed the sale of the assets of Challenger Minerals (Ghana) Limited. See Note 7—Discontinued Operations.