Patent ID: 8186912

Claim:
A method of installing a riser, said riser comprising a plurality of conduits extending from the seabed toward the surface and having an upper end supported at a depth below the sea surface by a buoyancy module, said riser being assembled at a place other than the installation site and transported thereto in a substantially horizontal configuration wherein said buoyancy module is attached to said riser by a non-rigid connection prior to said riser being upended to a substantially vertical working orientation, said riser and buoyancy module being transported together by a first, leading, vessel and second, trailing, vessel, the method further comprising the steps of: connecting said second vessel by a first line to the top end of the riser during transportation and paying in said first line to move toward the riser; rotating the buoyancy module approximately 90 degrees; making a permanent connection between said riser and buoyancy module on a service vessel; disconnecting a second line, which connected the top of the buoyancy module to the top of the riser during transportation, and passing said second line to said second vessel; disconnecting said first line; and initiating the upending of the riser.