A downhole apparatus comprises a casing string with a removable plug therein to block flow therethrough. A flow barrier is positioned in the casing below the removable plug and the removable plug and the flow barrier defining a buoyancy chamber therebetween. A debris barrier positioned above the removable plug includes a frangible disk. A stretchable connecting ring is connected to the frangible disk and to the casing.

A downhole apparatus comprises a casing string with a removable plug therein to block flow therethrough. A flow barrier is positioned in the casing below the removable plug and the removable plug and the flow barrier defining a buoyancy chamber therebetween. A debris barrier positioned above the removable plug includes a frangible disk. A stretchable connecting ring is connected to the frangible disk and to the casing.

A downhole apparatus comprises a casing string with a removable plug therein to block flow therethrough. A flow barrier is positioned in the casing below the removable plug and the removable plug and the flow barrier defining a buoyancy chamber therebetween. A debris barrier positioned above the removable plug includes a frangible disk. A stretchable connecting ring is connected to the frangible disk and to the casing.

An apparatus (1) for restricting the bending of a tubular member underwater comprises a plurality of interlocking modules each formed from a first half shell component (2) circumferentially displaced from a second half-shell component (3), wherein the first half shell component comprises one or more projections (19) extending from a side edge (18) thereof and the second half shell component comprises one or more grooves (21) in a side edge (18) thereof, the projections and grooves being angled to the side edges of the first and second half shell components, the arrangement being such that when assembled together each of the one of more projections of the first half shell component are inter-engaged with a corresponding groove of the second half shell component to secure the two half shells together.

A system for remediating a blockage in a subsea component including a riser extending from a surface vessel, a flexible jumper having an upper end coupled to the riser and a lower end coupled to a subsea component, and a surface system disposed on the surface vessel and including flexible tubing configured to be inserted and advanced through the tubular string and flexible jumper to the blockage.

An offloading system for conveying hydrocarbons from a buoyancy-supported subsea riser to a surface tanker vessel comprises a flexible hose that hangs from the riser structure in a U-shape having first and second limbs. An upper end of the first limb communicates with the riser and an upper end of the second limb terminates in a pulling head for connecting the hose to the tanker. A clump weight acts on a lowermost bend of the hose between the limbs to maintain tension in the limbs. A subsurface holder fixed to the riser structure is arranged to hold the pulling head against the tension in the second limb of the hose when the system is in a standby state. The holder is offset laterally from a central longitudinal axis of the riser structure and a counterweight is positioned to a side of that axis opposed to the holder.

A submarine connection for interconnecting a riser pipe and a flexible pipe (26). The riser pipe has an upper end and the flexible pipe (26) has a lower end (30). A connection assembly includes a rigid fitting having a first limb (64) to be connected to the lower end (30) and a second limb (66) with a connector (67) on the end, and a body (36) having a head (42) and an opposing base (46) provided with an end piece (52) to be mounted on the upper end. The connection assembly also includes first guiding elements (60, 86) secured to the body (36), extending in a position at a distance from the axis of the end piece (52), and second guiding elements (76, 81) secured to the first limb (64), suitable for cooperating with the first guiding elements (60, 86).

An underwater steel catenary pipeline riser (SCR) lifting frame comprises a lift frame foundation and an SCR lifting frame comprising a lift frame interface adapted to be connected to the lift frame foundation; a foundation interface; a lift guide configured to accept the lift frame foundation; and a lift slidably disposed about the lift guide, the lift comprising an SCR pull head interface configured to be connected to an SCR pull head. The underwater steel catenary pipeline riser (SCR) lifting frame and systems using it allow for flex joint repair/replacement subsea which do not require large winches, deck re-enforcements, steering winches, and heavy crane lifts required by facility mounted winches above water and also reduces required heavy lifting and overall complexity of flex joint replacement.

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.

A system for remediating a blockage in a subsea component including a riser extending from a surface vessel, a flexible jumper having an upper end coupled to the riser and a lower end coupled to a subsea component, and a surface system disposed on the surface vessel and including flexible tubing configured to be inserted and advanced through the tubular string and flexible jumper to the blockage.