Maersk Contractors is building four identical independent leg cantilever jack ups with an innovative XY cantilever design at Keppel FELS in Singapore. The first rig, the Maersk Resilient (Fig. 1), was named on Jan. 30, 2008, and will travel 3,472 nm nautical miles to Dubai for a 3-year contract with state-run Dubai Petroleum Establishment (DPE).1 The rig should arrive in Dubai by the end of this month, following a 3-week mobilization to the Persian Gulf.”
Design
The design team for the MSC CJO-X100 MC project (Fig. 2) included 20 experienced jack up rig crew and engineers from Maersk and Netherlands-based Marine Structure Consultants (MSC). The team incorporated features from two existing ultraharsh environment jack ups, Maersk Innovator and Maersk Inspirer, in the new design.
The new rigs have a large, open deck space of 2,143 sq m and will be equipped to drill deep, difficult wells, and handle high temperature and high-pressure conditions. The design includes automated systems that will speed up the drilling process and make it safer for righands. Dual assembly lines with 45-ft and 60-ft mouse holes will make it more efficient to build stands offline. The derrick is tall enough to accommodate drill pipe in stands of four joints (“fourbles”), although offline pipe handling and storage is limited to stands of three joints.
XY cantilever
The XY cantilever design was pioneered on the Maersk Innovator.1 The cantilever can skid transversely (X) as well as longitudinally (Y) and eliminates the need for a transverse skidding substructure. The rig can skid transversely and the rig can move with pipe in the derrick, saving time between wells, Maersk says.
The XY cantilever has a 70-ft reach from stern to well center and a transverse reach of 46 ft. Maersk can alter the design further, “similar to what was done to Maersk Inspirer,” where cantilever reach was extended to 100 ft from the original 90 ft.1
The cantilever deck is raised more than 3 m above the main deck, and the space underneath is available for storage. The length of the cantilever accommodates two pipe racks with capacity to store 30,000 ft of drill pipe (3½-in. to 65⁄8-in. diameter) and up to 13,330 ft of casing simultaneously.
Fluids
The rig has a 7,500-psi mud system with three Wirth TPK 7½-in. x 14-in., 2,200-hp pumps, and a slurrification unit with a 2,500-bbl slurry holding tank. There are 12 mud pits, including 4 slug or chemical pits and 4 mud storage tanks, with a total capacity of 6,000 bbl. There is an auto mixing system that reduces or eliminates manual mixing and a chemical dosing system that reduces human exposure to chemicals.
To handle mud returns, there are four Swaco BEM 650 shale shakers and two Swaco vacuum degassers.
A dual drilling fluid system allows rig hands to “hot swap” or easily change between mud and completion fluids.
Safety
A computer-assisted drilling system and mechanized pipe handling will provide a safer working environment on these new rigs. Maersk crews are being trained with 3D simulators that allow them to practice with software controlling all rig floor equipment. Workers also train on full-scale equipment at vendor sites.2
The drilling instrumentation system, Drill View, was designed by Maritime Hydraulics and is operated from chairs with joysticks and touch screens in an air-conditioned driller’s cabin. A CCTV camera is programmed to automatically follow the drilling sequence in order to offer the driller the best view of operations.
Handling
Tubulars are managed with a knuckle boom crane, automated pipe handler, block retract system, top drive, and Torque Master iron roughneck. The knuckle boom crane is installed on the cantilever deck and moves individual pipe joints to the tubular feeding machine; this eliminates the need for manual handling when pipe stands are made up or broken out. Stands are assembled and can also be stored on the cantilever deck.
The knuckle boom crane can also move nontubular equipment (subs, elevators) between the drill floor and the heavy tool storage area inside the cantilever.
The pipe racker can handle tubulars in the range of 3½-in. to 14-in. diameter.
The Torque Master is a new hybrid, which makes up drill pipe and casing and is equipped with a torque and turn system. It can handle tubulars in the range of 27⁄8-in. to 20-in. diameter (Fig. 3).
The Maritime Hydraulic DDM-750-AC top drive is powered by a single air-cooled AC motor. The drawworks and traveling block are grooved for 13⁄4-in. drill line.
The deck cranes have a static lift capacity of 80 tonnes and a dynamic lift capacity of 40 tonnes and are capable of lifting any coiled-tubing unit.
Comparison
The new MSC CJ50-X100 design is comparable to the Friede & Goldman (F&G) JU-2000A/E jack ups.3 4 The MSC and the JU-2000A are designed for 350-ft water depth (300 ft in harsh environments) and can drill to 30,000 ft. The JU-2000E is an extended-leg design and rated for 400 ft water depth. They all have triangular truss legs, an accommodation module that wraps around the forward leg, and deck cranes mounted on the jacking structures, increasing available deck space. The JU-2000A legs are slightly longer than the MSC design (493 ft vs. 479 ft) and the JU-200E legs are even longer at 548 ft.
The cantilever is slightly longer on both JU-2000 designs (75 ft vs. 70 ft for the CJ50-X100). Drilling capacities (cantilever and hook loads) are similar for the MSC design and the JU-2000A but slightly higher on the JU-2000E.
The Wirth drawworks of the CJ50-X100 offer 4,500 hp, but the drawworks on the JU-2000E are 3,000 hp.
The MSC design also has a taller derrick (210 ft vs. 170 ft on both JU-2000 designs) and accommodates 20% more personnel than the JU-2000A. But the JU-2000E is designed for a 750-tonne top drive, while the new MSC jack ups will have only 680-tonne top drives.
There is a large disparity in the fluid capacities. The MSC design includes larger storage for potable water (2,750 bbl vs. 1,531 bbl) and has slightly more bulk storage capacity (7,050 cu ft cement and 10,550 cu ft bulk mud)17,600 cu ft vs. only 15,750 cu ft on the JU-2000A. The MSC design also has larger liquid mud capacity6,000 bbl vs. only 3,745 bbl on the JU-2000A.
But the JU-2000 stores 21,270 bbl of drill water, considerably more than the 8,645 bbl (5,500 bbl drill water and 3,145 bbl brine) on the MSC CJ50-X100.
Dubai
Last year, the Emirate of Dubai took control of its four offshore fields (Falah, Fateh, SW Fateh, Rashid) and 70 platforms from Dubai Petroleum Co., a consortium led by ConocoPhillips (OGJ, Nov. 5, 2007, p. 66). UK-based Petrofac Ltd. and newly acquired subsidiary SPD LLC began a turnkey contract with the government to manage Dubai’s offshore facilities, production, and well operations on Apr. 2, 2007.
On Jan. 18, Petrofac announced a joint agreement with DPE to establish the Dubai Petroleum Training Center (DPTC) at DPE’s office in Dubai. The center will provide safety and technical training and will open mid-2008.
Fleet
Maersk owns and operates a fleet of 18 drilling units, including one semisubmersible, one 375-ft jack up, 6 ultraharsh environment jack ups, and 10 drilling barge rigs.
The company has eight additional rigs under construction, including the four new high-efficiency 350-ft jack ups discussed in this article, one new 375 ft jack-up rig, and three deepwater development semisubs.
The next three MSC 350-ft jack ups will be delivered from Keppel FELS over the next 15-20 months. All the other rigs will be delivered by 2010.
References
- “Welcome to the fleetMaersk Resilient,” Maersk Contractors, January 2008.
- “The Next Generation High Efficiency Jack-up,” Maersk Contractors, January 2008.
- “F&G JU-2000A,” 9 pp. brochure, Friede & Goldman, www.fng.com/pdf/JU2000a.pdf
- “F&G JU-2000E,” 2 pp. spec sheet, Friede & Goldman.