Moored in about 8,000 feet of water, the Perdido regional DVA (direct vertical access) spar is the deepest spar production facility in the world. Click to enlarge.

Tobago is jointly owned by Shell (32.5%, as operator), Chevron (57.5%), and Nexen (10.0%) and is one of three fields producing through the Perdido drilling and production platform.

Tobago breaks the world water depth record for subsea production, previously held by another field in the Perdido Development, the Silvertip field at 9,356 (2,852 m) feet of water.

Moored in about 8,000 feet of water, the Perdido platform is jointly owned by Shell (33.34%), BP (33.33%) and Chevron (33.33%) and is the deepest drilling and production facility in the world with a capacity to handle 100,000 barrels of oil per day and 200 million standard cubic feet of gas per day. From Perdido, Shell accesses the Great White, Tobago, and Silvertip oil and gas fields through subsea wells directly below the facility and from wells up to seven miles away.

This project began with the 1996 lease sale when the technology to develop hydrocarbons at Perdido’s water depth did not yet exist. By the time the final investment decision for commercial development was made in October 2006, Shell had pioneered several technological firsts which allowed the company to proceed with ultra deepwater oil and gas production. Development drilling began in July 2007, five years after the discovery of hydrocarbons. Perdido produced its first oil and gas on 31 March 2010.

Among Perdido’s technologies:

• The first use of water injection in 8,000 feet of water in the Gulf of Mexico (Great White GB001) to help push oil through the reservoir, from the injector wells to the production wells.

• An innovative subsea separation and boosting system that compensates for the low-pressure reservoir and about 2,000 psi of backpressure from the wells. The system includes five specially designed 1,500-horsepower electric pumps embedded in the seafloor to boost production to the surface.

• First spar with direct vertical access wells and production hardware on the seafloor at a depth of more than 8,000 feet. The 170-meter (555-foot) cylindrical Perdido spar was constructed by Technip in Pori, Finland. There are 22 direct vertical access wells from the spar, with an additional 13 tiebacks from subsea completions.

Perdido also marks the first commercial production from the Lower Tertiary geological formation, which many see as the next big opportunity in deep water.

Perdido itself weighs 50,000-tons. The entire Perdido project has achieved 13 million man-hours without a lost-time injury, according to Shell.

Resources

• Perdido Installation program: Transport & Installation (2008)