American Oil and Gas Reporter - June 2016 - 90

SpecialReport: Offshore Technology
Topsides Design
The main deck of the facility is 158 feet
above the water surface, and the production deck is 125 feet above water level. The
elevation of the top of the spar is 55 feet.
The maximum design weight of the topsides is 16,000 tons, with an initial weight
of 14,000 tons. Considerable flexibility is
built into the processing system, and the
separation facilities include a high-pressure/intermediate-pressure/low-pressure

primary oil train, an HP/IP/LP secondary
oil train, an HP gas train, and an HP test
separator.
Compression requirements are handled
by two single-motor-driven vapor recovery units and two gas engine-driven, flash
gas reciprocating compressors. Provisions also were made for two turbine-driven boost compressors. Power is provided
by three primary generators, an auxiliary
generator, and an emergency generator.

Accommodations are provided for a 44man permanent crew and an additional 24
temporary personnel. Two 60-ton cranes
provide the ability to load on both the east
and west sides of facility using reeled loading hoses.
To coordinate changes during design,
topsides fabrication and installation, a project change control system was used during various stages of the project, with captured changes related appropriately to
key drawings and documents during the
pre-startup review. Once the PSR was
complete and the facility was started, the
spar transitioned to the operations management of change procedures. Processes and
procedures complied with both internal
and external guidance on Gulf of Mexico
SEMS rules, but allowed the flexibility to
suit the particular phase of the project.
Topsides fabrication was undertaken at
Kiewit Offshore Services' yard at Ingleside, Tx. Large modules for the boost compressors, production system, fuel gas system, etc., were fabricated in Dolphin
Services LLC's facility in Houma, La. The
living quarters were fabricated at Beacon
Maritime in Orange, Tx.
The subcellar deck and temporary
work deck were assembled at Kiewit's
yard and integrated with the hull on location after the hull had been upended and
secured. A heavy lift vessel installed both
the hull and mooring, as well as the subcellar and temporary work decks, which
enabled the flowline risers and umbilicals
to be installed prior to shipping the main
deck to site.
All other topsides components were
shipped on different barges. The temporary work deck was removed and the topsides components were installed successfully and safely. Figure 5 shows a diagram
of the various lifts made on site.
Once on site, the accommodation vessel was used to quarter a construction
workforce of up to 500 during integration
and commissioning from April to December 2014. The vessel had an articulating
gangway that allowed continued access to
the topsides, and rest and meals away from
the main spar while it was being commissioned.
Export Lines
Enterprise Products Partners designed,
installed and operates the oil export
pipelines, while Discovery Producer Services (Williams) designed, installed and operates the gas export pipeline. The oil export is an 18-inch line that takes processed

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American Oil and Gas Reporter - June 2016

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