Pipelaying under way for Marathon's deepwater gulf projects

Global Industries Ltd.'s Chickasaw reel pipelay barge will lay pipe-in-pipe flow lines for Marathon Oil Co.'s Oyster and Arnold deepwater Gulf of Mexico development projects. Photo courtesy of Global.

Pipelaying has begun on flow lines for Marathon Oil Co.'s Oyster and Arnold oil field development projects in the Gulf of Mexico.

Global Industries Ltd., Houston, started work recently on contracts involving Oyster and Arnold work on Ewing Bank Blocks 917 and 963 in 1,250 ft and 1,800 ft of water, respectively.

Under a subcontract from ABB Offshore Technology, Global will weld and reel 8 miles each of dual 6-in. in 10-in. pipe-in-pipe insulated flow lines at Houma, La. The flow lines then will be reeled onto Global's Chickasaw reel pipelay barge. Global will lay the flow lines to connect the Arnold field development to a fixed platform about 8 miles away on Ewing Bank Block 873 in about 775 ft of water.

Under a separate contract with Marathon, Global will weld, reel, and lay 3 miles each of dual 3-in. in 6-in. pipe-in-pipe insulated flow lines to connect the Oyster development to its host platform 3 miles away.

After laying the flow lines, Global will use a remotely operated vehicle to pull the dual flow lines through a J-tube to link them with the fixed platforms. Under the subcontract with ABB, Global also will install a multiwell manifold at the Arnold development and connect the flow lines to the manifold. The Chickasaw will install the manifold by retrieving the pipeline and the insulated ends to the surface, welding the pipelines to the manifold, and then lowering the manifold to the seabed.

The Oyster and Arnold flow lines will be the third and fourth reeled pipe-in-pipe flow lines in the gulf-all laid by the Chickasaw, Global said. The company claims the Arnold insulated line will be the largest pipe-in-pipe flow lines ever laid in the gulf.

The Chickasaw also recently completed pipelaying of 63 miles of 3-in. glycol supply flow line to connect Shell Deepwater Development Inc.'s record deepwater Mensa development on Mississippi Canyon Block 685 to West Delta Block 143.

The Mensa flow line was installed in water as deep as 5,300 ft and included a vertical stab and hinge-over initiation to the Mensa subsea production manifold-among the deepest such initiations conducted, Global said.