A method of lowering a discrete load from a pipelay vessel comprises: holding a rigid rod on an upright launch axis where the rod extends through a hold-back system; coupling a lower end of the rod to the load; connecting a wire to the load directly; operating the hold-back system to advance the rod downwardly, hence submerging the load, while the weight of the load is suspended from the hold-back system via the rod; when the load is underwater and beneath the splash zone, transferring the weight of the load from the hold-back system to the wire by detaching the load from the rod while the rod is held by the hold-back system; and continuing to lower the load in the water, suspended directly from the wire. The method may be reversed to recover a load from a subsea location, such as when lifting a wellhead or blowout preventer from the seabed.
METHODS OF LOWERING AND RECOVERING LOADS IN SUBSEA OPERATIONS
METHODEN ZUM ABSENKEN UND EINHOLEN VON LASTEN IN UNTERWASSEROPERATIONEN
MÉTHODES D'ABAISSEMENT ET DE RÉCUPÉRATION DE CHARGES DANS DES MANOEUVRES SOUS-MARINES
12.10.2022
Patent
Elektronische Ressource
Englisch