Abstract: This method comprises connecting a downstream point (40) of a pipe (24) to a buoy (26) and completely submerging the buoy (26). It comprises deploying in the body of water (12) an intermediate section (30) of the pipe (24) from the downstream point (40) to at least as far as an upstream point (38), anchoring the upstream point (38), and tensioning the intermediate section (30) to keep it vertical. The connecting step includes activating a traction unit (96) to raise the downstream point (40) on the buoy (26). During the connecting step, the buoy (26) is carried in the body of water (12) virtually exclusively by its own floatability.

Abstract: This method comprises connecting a downstream point (40) of a pipe (24) to a buoy (26) and completely submerging the buoy (26). It comprises deploying in the body of water (12) an intermediate section (30) of the pipe (24) from the downstream point (40) to at least as far as an upstream point (38), anchoring the upstream point (38), and tensioning the intermediate section (30) to keep it vertical. The height of the buoy (26) is less than 1.5 times its greatest transverse dimension. The method comprises moving the buoy (26) between a remote position and an installed position in line with an anchoring region, keeping the buoy (26) partly submerged on the surface (16) of the body of water.

Abstract: An apparatus for venting an annular space between a liner and a pipeline of a subsea riser used for conveying hydrocarbons, the apparatus comprising a permeate recovery device for recovering permeate passing through the liner into the annular space. The permeate recovery device includes a first vent port in a wall of the pipeline at or adjacent a lower region of the pipeline and communicating with a permeate recovery line defining a flow path between the annular space and a permeate collection vessel. A one-way valve is associated with the permeate recovery line for preventing flow from the permeate recovery line into the annular space. A gaseous permeate recovery line connected to a second vent port at an upper region of the pipeline defining a flow of gaseous permeate from the annular space.

Abstract: This method comprises connecting a downstream point (40) of a pipe (24) to a buoy (26) and completely submerging the buoy (26). It comprises deploying in the body of water (12) an intermediate section (30) of the pipe (24) from the downstream point (40) to at least as far as an upstream point (38), anchoring the upstream point (38), and tensioning the intermediate section (30) to keep it vertical. The connecting step includes activating a traction unit (96) to raise the downstream point (40) on the buoy (26). During the connecting step, the buoy (26) is carried in the body of water (12) virtually exclusively by its own floatability.

Abstract: This method comprises connecting a downstream point (40) of a pipe (24) to a buoy (26) and completely submerging the buoy (26). It comprises deploying in the body of water (12) an intermediate section (30) of the pipe (24) from the downstream point (40) to at least as far as an upstream point (38), anchoring the upstream point (38), and tensioning the intermediate (section (30) to keep it vertical. The height of the buoy (26) is less than 1.5 times its greatest transverse dimension. The method comprises moving the buoy (26) between a remote position and an installed position in line with an anchoring region, keeping the buoy (26) partly submerged on the surface (16) of the body of water.

Abstract: An apparatus for venting an annular space between a liner and a pipeline of a subsea riser used for conveying hydrocarbons, the apparatus comprising a permeate recovery device for recovering permeate passing through the liner into the annular space. The permeate recovery device includes a first vent port in a wall of the pipeline at or adjacent a lower region of the pipeline and communicating with a permeate recovery line defining a flow path between the annular space and a permeate collection vessel. A one-way valve is associated with the permeate recovery line for preventing flow from the permeate recovery line into the annular space. A gaseous permeate recovery line connected to a second vent port at an upper region of the pipeline defining a flow of gaseous permeate from the annular space.

Abstract: A shallow water riser extending between a seabed connection and a floating support connection and of a length through the shallow water to be in wave form with at least one and, as illustrated, two wave areas in contact with the seabed. A protective sheath optionally surrounds the riser at the contact regions with the seabed. The upraised wave portions are supported by float elements.

Abstract: A shallow water riser extending between a seabed connection and a floating support connection and of a length through the shallow water to be in wave form with at least one and, as illustrated, two wave areas in contact with the seabed. A protective sheath optionally surrounds the riser at the contact regions with the seabed. The upraised wave portions are supported by float elements.

Abstract: A device for eliminating propagation of a buckle in the outer wall of a double-walled tube, where the double-walled tube comprises an outer pipe, an inner pipe and an annular space between them in which the deformable element is disposed with the external surface of the deformable element in contact with the internal wall of the outer pipe and the interior of the deformable element being spaced outward from the inner pipe and having a sheath on the interior of the deformable element. The deformable element may be a wound wire, a profiled wire, an interlocked wire with interlocked turns, a non-interlocked wire, a spring with turns urged outwardly or reinforcement with turns urged outwardly and bearing blocks in the annular space on the inner pipe for at least one end of the reinforcement.