GlobalSantaFe has taken delivery of one of the world's latest heavy duty jackup rigs which is designed to be one of the most versatile on the market.

The GSF Constellation 1 is fitted with a 108-ft (32.9-m) cantilevered deck which accommodates a knuckle-boom crane providing horizontal to vertical pipe-handling from pipe deck to derrick. It can handle casing doubles and drillpipe trebles - improving pipe-handling capability.

Consequently the rig crew can make up and break up drilling and casing joints in sizes up to 183/4-in. offline.

Also there is an element of future proofing, with provision for cuttings handling equipment designed into the cantilever, to meet expected future environmental requirements for total cuttings removal to shore. This rig is built for zero discharges to sea and has containment systems for all present environmental constraints and concerns, claims the rig owner.

The Constellation 1 is a Friede and Goldman JU2000 design with an operational water depth rating to 400 ft (122 m). Built at the PPL shipyard at Jurong, Singapore, the new rig is rated for a drilling depth of 30,000 ft (9,150 m) and has a drilling load capacity of 2.6 million pounds.

In designing the rig, Friede and Goldman indicated their JU2000 concept would be geared towards all-year Central North Sea-type harsh environment operations. "This unit is designed to meet the 50-year return environmental conditions in according with classification society assessment criteria," F&G indicated. However, with the less-challenging environment in which the Constellation 1 is due to operate initially - offshore Myanmar in the Asia Pacific region - it will be capable of tackling water depths up to 400 ft (122 m). This is possible with its standard leg length of 548 ft (167 m) and 36 pinions on the jacking system. "Greater operating water depths are possible with the installation of additional pinions, increased hull size and extended leg length," F&G said.

"The Constellation 1 is designed to increase drilling efficiency and to perform beyond traditional exploration and development drilling requirements," Global's president and chief executive Jon A. Marshall said.

Most of the rig equipment - drawworks, rotary table, top drive and pipe-handling is by National Oilwell, as well as the drilling control system.

Some changes are made from the original F&G JU2000 specification to provide GSF with the Constellation 1.

Power is from a five-motor DC system using five Ross Hill units which power 10 GE 752 DC motors, differing from the original JU2000 concept. Also, AC power is supplied by five Caterpillar 3561B diesels giving between 9,275 horsepower - 1,855 horsepower apiece - which drive five 2,150 kVa generators, again differing from the JU2000 template.

Blowout preventer (BOP) handling is by a 125-ton bridge crane with telescopic forks that allow the BOP to be placed anywhere within a 3-D envelope of the wellhead handling area. Two 15-ton cranes in the BOP storage area provide handling for BOP stacks and subsea trees.

Like Transocean's Tri-act rigs, mechanization and speed of equipment movement on the drillfloor is key to getting the unit to operate faster.

Storage is provided for up to 5,000 bbl of liquid mud, 900 bbl of brine, and 18,280 cubic feet of bulk material, 12,315 bbl of drilling water and there is room for 5,000 sacks of chemicals.

This rig also has three cranes - port starboard and aft, in addition to the knuckle boom crane. Global's Constellation 1 features a 170-ft (52-m) drilling derrick with 1,600,00-lbs of hookload capacity. The 3,000 horsepower drawworks has three GE 752 DC motors, disc brakes and an auxiliary eddy current brake.
The Constellation 1 was initially contracted for four months offshore Myanmar on a three-well platform development drilling program worth approximately US $8.8 million, working for a joint venture between Premier Oil and Petronas which was scheduled to commence mid August.

In 2004, GlobalSantaFe is due to take delivery of a sister rig, dubbed the Constellation II.