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.
HANDLING LOADS IN SUBSEA OPERATIONS
HANDHABUNG VON LASTEN IN UNTERWASSEROPERATIONEN
MANIPULATION DE CHARGES DANS DES OPÉRATIONS SOUS-MARINES
2023-02-08
Patent
Electronic Resource
English