Transocean says that its ultra-deepwater semisubmersible rig Deepwater Horizon recently drilled the deepest oil and gas well ever while working for BP and its co-owners on the Tiber well in the U.S. Gulf of Mexico. Working with BP, the Transocean crews on the Deepwater Horizon drilled the well to 35,050 vertical depth and 35,055 feet measured depth (MD), or more than six miles, while operating in 4,130 feet of water.

"This impressive well depth record reflects the intensive planning and focus on effective operations by BP and the drilling crews of the Deepwater Horizon," said Robert L. Long, Transocean Ltd.'s Chief Executive Officer. "Congratulations to everyone involved."

These achievements are the latest in Transocean's history of world and other records dating back to the 1950s. In 2005, the ultra-deepwater drillship Discoverer Spirit set the record for the longest Gulf of Mexico oil and gas well at 34,189 feet, MD. Most recently, the Transocean jackup GSF Rig 127 drilled the industry's longest extended-reach well in 2008 while working for Maersk Oil Qatar AS at 40,320 feet MD with a 35,770-foot horizontal section. The well was drilled offshore Qatar in 36 days and was incident-free.

Transocean also holds the current world water-depth record of operating in 10,011 feet of water set while working for Chevron in the U.S. Gulf of Mexico.

The Deepwater Horizon, placed into service in 2001, is a dynamically positioned ultra-deepwater semisubmersible rig capable of working in water depths of up to 10,000 feet.