Abstract: 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.

Abstract: A tensioner system holds back elongate products such as subsea pipelines being laid into water. The system comprises at least one endless circulatory track and an array of rollers supporting the track. Each of the rollers of the array is mounted for rotation around a respective shaft. At least one of the shafts comprises a load pin that is arranged to sense loads applied to the surrounding roller in directions normal to an axis of rotation of that roller.

Abstract: An end fitting for a subsea riser comprises an engagement head to be engaged with a subsea foundation in a vertically downward longitudinal direction. A structure of the end fitting surrounds a longitudinally extending flow axis and is arranged to bear a tensile load on a load path extending longitudinally from the engagement head parallel to the flow axis. The structure includes a pivot joint assembly having a first part attached to or integral with the engagement head and a second part pivotable relative to the first part about a centre of rotation substantially aligned with the flow axis. The structure can be fixed to the engagement head or removably attached to the engagement head. The engagement head supports an upwardly facing connector hub that is offset laterally from the flow axis. A connector pipe in fluid communication with the connector hub extends from the flow axis to the connector hub. A counterweight is opposed to the connector hub and the connector pipe about the flow axis.

Abstract: Lined pipelines with different inner diameters are spooled successively onto a reel while their constituent pipe stalks are cyclically pressurised internally to combat wrinkling of the liner. A first, variable diameter pig is advanced to a trailing end of a first pipeline. A transition joint is attached to the trailing end of the first pipeline to effect a transition from the inner diameter of the first pipeline to the different inner diameter of a second pipeline. A leading end of the second pipeline, containing a second pig, is attached to the transition joint. The first pig is driven through the transition joint into the second pipeline. The diameter of the first pig changes to match the inner diameter of the second pipeline. The first and second pigs are then driven along the second pipeline when assembling the second pipeline from a succession of pipe stalks.

Abstract: In a method of joining a structure to a water-filled pipeline aboard a reel-lay vessel, a trailing end portion of the pipeline is suspended upright on a reel-lay tower. Water is drained from the trailing end portion while being retained in an inclined portion of the pipeline extending from the tower to a reel of the vessel and in a spooled portion of the pipeline coiled on the reel. The structure is joined to a trailing end of the pipeline after inserting a pig into the trailing end portion through the trailing end. Pumping additional water into a leading end of the pipeline on the reel propels the pig from the trailing end portion into a conduit of the structure while flooding the trailing end portion. This expels air through a port of the structure that was trapped in the trailing end portion between the pig and the structure.

Abstract: A pliant link to mitigate fatigue-inducing motion of a subsea catenary riser has an articulated spine having a longitudinal series of interconnected rigid segments. The spine can be coupled to upper and lower sections of the riser to transmit loads along the riser through the link on a load path that extends through the segments. The link also has a pliant pipe terminating in end fittings that can be joined, respectively, to the upper and lower sections of the riser for fluid communication along the riser through the link.

Abstract: A pulling and alignment system for flanged components has pairs of flange attachments fixed to respective flanges of components that are to be pulled together and aligned for coupling. A puller device is supported by a flange attachment of each pair. A flexible elongate pulling link extends between the flange attachments of the pair and is engaged by, and movable relative to, the puller device to act in tension between those flange attachments. Each flange attachment is a flange extension that comprises an arm cantilevered from a mounting to extend beyond the flange and to hold the pulling link outboard of the flange. The pulling link is an articulated rod having a longitudinal series of rigid elements, each of those elements being pivotably coupled to at least one other of those elements.

Abstract: A top connection arrangement for a subsea riser comprises a pivot or joint combination disposed between, and fluidly connecting, upper and lower sections of rigid pipe. The pivot combination comprises an upper ball joint about which the upper pipe section is pivotable. A lower joint, being a flexible joint or a tapered stress joint to which the lower pipe section is attached, is fixed to the ball joint in series. A sleeve is fixed to the ball joint and surrounds the upper pipe section to permit limited pivotal movement of that pipe section about the ball joint. The sleeve may seat into the bellmouth of an I- or J-tube of a surface facility or may be omitted if the lower joint is seated in a hang-off formation. A locking mechanism is capable of locking the ball joint and hence preventing pivotal movement of the upper pipe section.

Abstract: A top connection arrangement for a subsea riser comprises a pivot or joint combination disposed between, and fluidly connecting, upper and lower sections of rigid pipe. The pivot combination comprises an upper ball joint about which the upper pipe section is pivotable. A lower joint, being a flexible joint or a tapered stress joint to which the lower pipe section is attached, is fixed to the ball joint in series. A sleeve is fixed to the ball joint and surrounds the upper pipe section to permit limited pivotal movement of that pipe section about the ball joint. The sleeve may seat into the bellmouth of an I- or J-tube of a surface facility or may be omitted if the lower joint is seated in a hang-off formation. A locking mechanism is capable of locking the ball joint and hence preventing pivotal movement of the upper pipe section.

Abstract: 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.

Abstract: A size-adjustable, pivotable triple-connection device is disclosed. The device has a first element with an upper hole and a lower hole and a second element with an upper hole and a lower hole. The second element is pivotable in relation to an axis of alignment of upper holes of the first and second elements, and aligning, when not connected by its lower hole, in relation to a vertical axis of the first element. The device also has a shackle with a pin that traverses the axis defined by the alignment of the upper holes of the first and second elements.