|
Gorilla Transformed:
ABS Helps Ready Bob Palmer Jackup for Gulf of Mexico
|
ABS
Surveyor John T. Preston examines the Bob
Palmer jackup rig, christened at LeTourneau’s
Sabine Pass yard. Classed by ABS as an XA1
self-elevating drilling unit, CDS, the rig is
a LeTourneau design that is able to drill in
waters up to 550 feet in tropical storm locations
such as the Gulf of Mexico.
|
|
|
 |
s part of its ongoing activities to assist
industry with frontier exploration and |
development, ABS recently classed the newly christened Bob
Palmer jackup rig, a mobile offshore drilling unit (MODU)
owned by Rowan Companies.
Classed as an XA1
self-elevating drilling unit, the Bob Palmer is designed
to drill in water depths up to 550 feet in tropical storm
locations such as the Gulf of Mexico. The unit’s first
assignment is to drill a 25,000-foot well in the Gulf of Mexico.
John Preston, ABS Surveyor, advises that the new unit also
carries the ABS Certified Drilling System (CDS) additional
classification notation. “CDS classification is not
required by regulation for this unit, but the owners wanted
to go above and beyond the call of duty for this upgraded
design,” said Preston.
|
The Bob Palmer is an enhanced version of the Rowan Super
Gorilla-class jackup design and is designated as a Super Gorilla XL.
The new unit carries the name of a major player in the company’s
history, C. Bob Palmer, former Chairman and CEO of the Rowan Companies.
Structural modification and enhancement of previous jackup designs
exemplifies the growing need for improved efficiency and increased
capacity in the world’s aging fleet of jackup units, says
John Preston.
“As developers redesign existing units for use in deeper
waters and harsher environments, we provide the expertise that customers
need to ensure that all structures are fit for intended purpose
and meet international requirements,” said Preston.
In addition to the standard considerations for ABS classification,
including materials selection, load considerations and hull criteria,
the structural survey of the new jackup unit presented several challenges.
“Structures designed or redesigned for deeper waters require
more extensive ground-level surveys. When elevated, the unit had
the world’s highest leg-up to date and the largest air gap,
presenting us with an expanded envelope of survey parameters,”
said Preston.
The rig is outfitted with three legs, each 713 feet long (139
feet more than Gorillas V, VI or VII), and has 30 percent larger
spud cans enabling operation in up to 550 feet of water in the hostile
environments offshore eastern Canada and in the North Sea.
ABS provides classification and certification services for more
than 75 percent of the world fleet of MODUs. The ABS publication
Rules
for Building and Classing Mobile Offshore Drilling Units sets
out requirements for materials and welding; hull and equipment;
machinery; and surveys after construction.
Addressing a broad range of issues, ABS recently released a detailed
technical commentary to the MODU Rules. This commentary gives owners
more detailed guidance on the application of the Rules, particularly
those sections applicable to self-elevating jackup units and modified
rigs.
“The commentary is a further step in providing industry
more case-specific direction on how to apply ABS Rules to this sort
of modification and new design,” said Preston.
For more information on the updated Guide for the Certification
of Drilling Systems, visit the ABS newsroom at: http://www.eagle.org/news/press/oct2203.html
|
