Transocean Ultra-Deepwater Drillship Contract

Transocean Ltd. (NYSE:RIG) announced that the Discoverer Clear Leader has commenced operations for Chevron U.S.A. Inc., a wholly owned subsidiary of Chevron Corporation (NYSE:CVX), in the U.S. Gulf of Mexico under a five-year drilling contract. The Discoverer Clear Leader is the first of five Transocean ultra-deepwater enhanced Enterprise-class drillships scheduled to commence operations in 2009 and 2010.

The dynamically positioned, double-hulled Discoverer Clear Leader includes the most advanced drilling capabilities in the offshore drilling industry. The vessel is an enhanced version of Transocean's three predecessor Enterprise-class drillships, which have set deepwater drilling records in recent years, including the world water-depth drilling record of 10,011 feet set by the Discoverer Deep Seas while working for Chevron in the U.S. Gulf of Mexico.

The Discoverer Clear Leader's features include Transocean's patented dual-activity drilling technology, which allows for parallel drilling operations designed to save time and money in deepwater well construction, compared with conventional rigs. The dual-activity technology, along with a new and enhanced top drive system, an expanded high-pressure mud-pump system, expanded completions capabilities and other unique features of the drillship target the drilling of wells up to 40,000 feet of total depth. The rig also has a variable deckload of more than 20,000 metric tons and the capability of drilling in water depths of up to 12,000 feet.

In addition to the Discoverer Clear Leader, Transocean has four other enhanced Enterprise-class drillships in various stages of construction or preparation for initial contracts which are scheduled to commence operations in 2009 and 2010. Those four vessels, all of which have drilling contracts, are the Discoverer Americas, Discoverer Inspiration, Discoverer India and Discoverer Luanda. Another four Transocean newbuild ultra-deepwater floaters, which also have drilling contracts, are scheduled to commence operations in the next two years, including the Deepwater Champion, Dhirubhai Deepwater KG2, Petrobras 10000 and Development Driller III.