BP America Production Co. (BP) developed a deepwater pipeline infrastructure in the Gulf of Mexico, to carry the product from the Holstein, Mad Dog, Thunder Horse and Atlantis field developments.

These developments include large floating production systems that combine drilling and production facilities, top tensioned riser and dry trees as well as wet trees. The export of the oil and gas will be via the Mardi Gras Transportation System pipelines.

HMC performed the Project Management, Engineering fabrication and Offshore Installation of the Mardi Gras Export Pipelines. The project comprised a total of 400-km of 28- inch, 26-inch, 24-inch, 18-inch and 16-inch pipelines with 13 Inline Wye-pieces, 5 Pipeline Termination Assemblies and 8 Steel Catenary Risers, Atlantis pipe-in-pipe SCR's and flowlines.

The Inline wye-pieces weigh over 100 t each and were the biggest ever installed in these water depths at the time.

Main Characteristics

Offshore Start Date: 2004-Q1
Offshore End Date: 2007-Q4

Main Spread
Vessel: --
Transport Vessel(s): Balder
Hamers: --

Main Technical Data
Pipelines: Diameter: up to 28"
Wye Sled Assemblies: 14 Inline wye sled Assemblies - Diameter: 16" - 28"
End Sled Assemblies: 5 Pipeline End Sled Assemblies - Diameter: 16" - 24"
5 Jumpers: >100 ft in length