Close 

Drillship construction cycle nears end


The drillship construction cycle that began 3 years ago is nearing completion with delivery of Global Marine Inc.'s Glomar Jack Ryan. The two remaining drillships still on order�R&B Falcon Inc.'s Deepwater Discovery and Transocean Sedco Forex Inc.'s Discoverer Deep Seas�should join the fleet by yearend.

Christened Oct. 7 in Galveston, Tex., the 759-ft long Jack Ryan will depart for Trinidad and Tobago in early November to begin a 3-year contract for ExxonMobil Corp.

Global Marine will receive a day rate of about $195,000 for the drillship.

The vessel has a streamlined hull that allows transit speeds of up to 13.52 knots. While drilling, the Jack Ryan will maintain station within 1 m through the assistance of six fully retractable thrusters, a differential global positioning system, and an acoustic backup. A mirror DGPS, along with other redundant systems such as radar scopes, gyros, and echo sounders, are located away from the bridge to increase safety in the event of marine distress.

Drilling equipment
Currently equipped with 8,000 ft of riser, the ultradeepwater vessel will be able to drill in 12,000 ft of water with additional riser. Rated drilling depth is 35,000 ft.

Pipe-handling capabilities include vertical and horizontal systems. The vertical system will be used to make up bottomhole assemblies, landing strings, and casing strings offline while the horizontal system will be dedicated to drilling and tripping operations.

Operators will handle the drillstring from an automated driller's cabin that links the top drive, pipe-handling equipment, iron roughneck, and auxiliary mousehole through programmable logic circuit control panels.

Drilling equipment includes an 18-ft tall, 2 million-lb static hook-load mast with ten 2.5 million-lb riser tensioners. The active mud system is equipped with three 7,500-psi triplex mud pumps.

The 60-ft tall, 300-ton blowout preventer (BOP) module includes:

� Two 18 3/4-in., 15,000-psi double ram BOPs.

� Two 18 3/4-in., 15,000-psi single-ram BOPs.

� One 18 3/4-in., 15000-psi wellhead connector.

� Two 18 3/4-in. 10,000-psi annular BOPs.

A remotely operated vehicle uses retractable arms and video monitors to maintain and repair the BOP.

Living quarters will accommodate 150 people and amenities include a 60-seat movie theater. There are four 75-person lifeboats, a medic room, and first aid facilities.


To access this Article, go to:
http://www.ogj.com/content/ogj/en/articles/2000/10/drillship-construction-cycle-nears-end.html