Page 100: of Offshore Engineer Magazine (May/Jun 2013)

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Pipelines

Reeled Pipelay Vessel for Ultra- deepwater Field Developments

Lewek Constellation multipurpose lay

By John Meenaghan and Erik Christiani- thus have to be mobilized from vessel and subsea construction vessel

EMAS AMC, Houston established regions. This also cre- with four fully loaded vertical reels on

Reeled pipelay has normally been ates a logistical challenge, as most board.

used in fully developed and matured of these areas do not have spoolbase offshore oil and gas feld areas with and shorebase support facilities close proximity to onshore support, within a reasonable transit distance. (OD), a 900Te hang-off module, and onshore logistics, and with short a movable/adjustable work platform offshore transit distance to onshore Specifcations along the tower. The tower can be spoolbases for loading the pipeline The Lewek Constellation is an inno- adjusted from 60° to 90° to accom- stalks onto the reel. This activity nor- vative, state-of-the-art, DP 3, ice-class modate pipe laying from shallow mally requires comprehensive plan- pipelay vessel that not only has the water to ultra-deepwater. The A&R ning both onshore and offshore, and ability to install multiple risers, system has two 600Te traction is often on the pipelay’critical path. fowlines, fexibles, umbilicals, and winches and a 125Te secondary

New discoveries in remote loca- platforms in a feld, but also can do winch.

tions, such as the Brazilian pre-salt so in remote locations. The vessel In rigid reel lay, the vessel can and post-salt developments, often has a multi-lay system and heavy- apply up to 800Te of dynamic top have long transit times from estab- lift capabilities. By using a portable tension on fowlines and rigid risers lished spoolbases and port facilities, reel system, the vessel is able to stay up to 16in. nominal OD. In fexible rendering certain reeled lay scenar- in the feld or in close vicinity, thus mode, the vessel and lay system can ios uneconomical. To reach the post- taking reeling operations off the criti- accommodate sizes up to 24in. nom- salt and pre-salt reservoirs in Brazil cal path and maximizing the vessel’s inal OD, while applying 400Te and and West Africa and the Miocene operational time. 430Te of top tension, respectively.

and Lower Tertiary subsalt zones in The vessel’s multi-lay system the Gulf of Mexico, it is necessary (MLS) is comprised of an 800Te Spooling barge for operators to drill wells in deep tiltable tower, a 60Te pipeline end The pipelay vessel will use a spool- and ultra-deep water in increasingly termination (PLET) handling system ing barge with a ballasting system remote regions. for large PLETs, and a 1200Te A&R to manage the heel and trim of the

This presents a challenge for system. The tower has dual 400Te reels. The barge will be outftted operators as subsea construction tensioners, a straighter for handling with a spooling system that includes services are not always readily pipe-in-pipe fowline systems with a feeting roller track assembly, available in remote locations and outer pipe up to 16in. outer diameter a feeting tensioner, a reel cradle

OE | May 2013 oedigital.com 102 fp2.indd 102 4/22/13 6:17 PM