Cameron Highway Oil Transport System, Gulf of Mexico, USA

The Cameron Highway is a deepwater crude oil transport system with a capacity of 600,000b/d. It stands as the longest offshore oil pipeline in the US, measuring in excess of 390 miles. It is the first to bring multiple production streams from the Louisiana Gulf to the main hubs of Texas City and Port Arthur.

The Cameron Highway starts at the Block 332 hub, receiving oil from Holstein / Mad Dog / Atlantis, as well as Constitution / Ticonderoga. The network consists of a gathering platform on Ship Shoal 332. The 30in line then runs 240 miles along the US Outer Continental Shelf. It stretches west to a platform on Garden Banks 72 and then north-west to High Island A5. At this point, a dual, 24in line runs 69 miles to Texas City and another 70 miles to Port Arthur.

At Texas City is the 450,000b/d BP refinery, scene of the unfortunate 2004 explosion, as well as the 243,000b/d Valero refinery. At Port Arthur, is the 250,000b/d Premcor refinery, the Premcor Lucas terminal, the Sunoco Nederland terminal and the Unocal Belmont terminal.

The installation of the 30in line was carried out in stages and completed by late 2004. It was installed by the Allseas dynamically-positioned pipelay vessel Solitaire, with the Trenschsetter and Digging Donald used for pipeline burial.

It laid the wet pipe at a rate of 475 joints, or 3.6 miles, per day. Once the line was laid, Torch installed 1,600 post-crossing mats.

To accommodate the 62 pipeline and cable crossings along the offshore route, as many as 2,000 concrete mattresses were installed prior to the pipelay operations, helping to reduce load and stress levels on the pipeline. Each of these concrete mattresses measured 30ft by 9ft by 1ft and were installed using ROVs supplied by Oceaneering.

SHIP SHOAL 332B

Wanting to build a superdeck at its existing platform, Enterprise was forced to build a new platform when the regulatory bodies rejected this original proposal. This added a cost of $60 million to the project.

SS332B uses a design previously used on Falcon Nest, enabling long lead-time materials to be ordered. Enterprise was able to design and build the platform in only 13 months. The structural engineering was provided by Petro-Marine / BCI while the facilities engineering contract went to Mustang.

Gulf Island Fabrication fabricated the 4,000t jacket and pilings. Dynamic Industries were responsible for the deck and 210ft bridge construction.

Positioned in 430ft of water, Heerema Marine used its Hermod heavy lift vessel to install the jacket, cellar deck and the bridge that links the new SS332B plat form with the original SS332A. The upper deck section was installed by J Ray McDermott's DB-16 and Shear Leg 5000.

GARDEN BANKS BLOCK 72

The GB72 platform deck lies in 520ft of water. Fabrication work was carried out by Dynamic industries to extend the deck. The two 30in steel risers to connect with the pipeline were installed by Horizon Offshore using its Atlantic vessel. The riser clamps and guards were installed by Cal Dive and Stolt while the subsea tie-in spools were supplied by Global using saturation diving carried out from the Pioneer.

HIGH ISLAND A5C

The third major offshore construction was the receiving and pumping platform built at High Island A5C. The simple platform jacket was constructed by Unifab International and installed using Horizon's America Horizon in 65ft of water. It was secured by four piles.

The 2,800t deck was installed by J Ray McDermott's DB-50, with Dynamic Industries carrying out hook-up. Global not only installed the 30in tie-in spool, but also 4 miles of 6in line to connect the subsea gas fuel supply.