A method of launching an elongate subsea structure such as a pipeline bundle unit into water provides buoyant support to the structure by displacing water with a hollow buoyancy unit that applies buoyant upthrust to the structure. By lowering the buoyancy unit in the water to bring a permanently open aperture of the buoyancy unit beneath a surface level of the water, the buoyancy unit is flooded with water through the or each permanently open aperture to reduce the buoyant upthrust applied to the structure.

A method of launching an elongate subsea structure such as a pipeline bundle unit into water provides buoyant support to the structure by displacing water with a hollow buoyancy unit that applies buoyant upthrust to the structure. By lowering the buoyancy unit in the water to bring a permanently open aperture of the buoyancy unit beneath a surface level of the water, the buoyancy unit is flooded with water through the or each permanently open aperture to reduce the buoyant upthrust applied to the structure.

A hang-off insert for hanging-off a flexible elongate subsea element from a surface vessel has a circular loop that includes circumferentially-spaced support segments. Collectively, the segments define a substantially planar support face of the insert and have respective radially inner faces that define an inner radius of the loop. The radially inner faces of the support segments can be positioned at various radial positions to determine the inner radius of the loop and hence to adapt the circumference of the loop to suit different diameters of elongate subsea elements. With the hang-off insert supported by a hang-off structure of the vessel, a laterally-protruding hang-off feature of the elongate subsea element extending through the loop may be rested on the support face to transfer suspended weight loads to the hang-off structure.

A hang-off insert for hanging-off a flexible elongate subsea element from a surface vessel has a circular loop that includes circumferentially-spaced support segments. Collectively, the segments define a substantially planar support face of the insert and have respective radially inner faces that define an inner radius of the loop. The radially inner faces of the support segments can be positioned at various radial positions to determine the inner radius of the loop and hence to adapt the circumference of the loop to suit different diameters of elongate subsea elements. With the hang-off insert supported by a hang-off structure of the vessel, a laterally-protruding hang-off feature of the elongate subsea element extending through the loop may be rested on the support face to transfer suspended weight loads to the hang-off structure.

A device for paying out an elongated flexible article from a vessel is described. The device comprises a storage unit for the article, overboarding guide means for the article, article support means defining a cable path between the storage unit and the overboarding guide means, and pulling means for advancing the elongated article along the path. The article support means comprise an overboarding support element that is translatable in a first direction, and a buffering support system comprising a support element that is translatable in a second direction, whereby a translation of the support element has the effect of varying the length of the cable path. A vessel equipped with the device is also described. The device and method allow paying out an elongated flexible article from a vessel in a more efficient way.

A device for paying out an elongated flexible article from a vessel is described. The device comprises a storage unit for the article, overboarding guide means for the article, article support means defining a cable path between the storage unit and the overboarding guide means, and pulling means for advancing the elongated article along the path. The article support means comprise an overboarding support element that is translatable in a first direction, and a buffering support system comprising a support element that is translatable in a second direction, whereby a translation of the support element has the effect of varying the length of the cable path. A vessel equipped with the device is also described. The device and method allow paying out an elongated flexible article from a vessel in a more efficient way.

Deployment of coiled tubing may be assisted using an apparatus comprising a source of coiled tubing, a coiled tubing distributor that comprises a passageway adapted to allow engaging the coiled tubing from the source of coiled tubing where the passageway comprises a coiled tubing receiver comprising a predetermined radius and a support frame, connected to the passageway, that is adapted to accept a portion of the coiled tubing therethrough, and a slip disposed intermediate the passageway and the support frame where the slip is adapted to accept a portion of the coiled tubing therethrough. The apparatus may be mounted to a structure and a portion of the coiled tubing deployed from the source of coiled tubing about the coiled tubing receiver through the slip. The apparatus is allowed to compensate for motion of the structure while the portion of the coiled tubing is deployed about the coiled tubing receiver through the slip.

Deployment of coiled tubing may be assisted using an apparatus comprising a source of coiled tubing, a coiled tubing distributor that comprises a passageway adapted to allow engaging the coiled tubing from the source of coiled tubing where the passageway comprises a coiled tubing receiver comprising a predetermined radius and a support frame, connected to the passageway, that is adapted to accept a portion of the coiled tubing therethrough, and a slip disposed intermediate the passageway and the support frame where the slip is adapted to accept a portion of the coiled tubing therethrough. The apparatus may be mounted to a structure and a portion of the coiled tubing deployed from the source of coiled tubing about the coiled tubing receiver through the slip. The apparatus is allowed to compensate for motion of the structure while the portion of the coiled tubing is deployed about the coiled tubing receiver through the slip.

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 either directly or indirectly via the rod; 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 under mater and beneath the splash zone, transferring the weight of the load directly or indirectly from the hold-back system to the wire; and continuing to lower the load in the water, suspended directly or indirectly 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.

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 either directly or indirectly via the rod; 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 under mater and beneath the splash zone, transferring the weight of the load directly or indirectly from the hold-back system to the wire; and continuing to lower the load in the water, suspended directly or indirectly 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.