Patent ID: 7011473
Filing Date: 2006-03-14
Classification: B63B,B63C,E02B,E02D,E21B

Abstract:
1. A method for transport and installation of objects at sea, particularly relating to transport and installation of subsea objects that are part of the infrastructure in oil and gas fields offshore, where the object is put in the sea at a suitable location near the shore or in sheltered waters, then towed to the installation site while being suspended via a suspension arrangement of a predetermined length in at least one floating buoyancy unit, and subsequently lowered to its final destination, wherein use is made of at least one slender upright buoyancy unit, which also is used as a heave compensator during the towing and thereby reduces the dynamic loads in the towed object and the suspension arrangement between the towed object and the buoyancy unit, and that upon arrival at the installation site, the suspension of the object is transferred from said at least one buoyancy unit to a heave compensated winch on a surface vessel while the buoyancy unit is disconnected, said winch being used to lower the object to its destination on the sea bottom or a predetermined location above the sea bottom.