Abstract: A system of liason between an underwater wellhead for the production of hydrocarbons from underwater formations to a surface support. The system includes at least one flexible conduit (4) connected between the wellhead (2) and the surface support (1). Each flexible conduit is equipped at its lower end with means to limit the radius of bending or deflection and is connected vertically to the wellhead. Each conduit can be pulled or led into at least a first configuration (4a, 4'a, 4"a) in which the conduit is generally relaxed and non-tensioned, for the flow of hydrocarbons to the surface support, and at least a second configuration (4b), in which the conduit is at least partly tensioned, and sufficiently straight and upright that tools can be lowered to descend by gravity from the support surface to the well, for working of the well.

Abstract: A flexible buoyant conduit which includes a thermoplastic pressure-resistant stratum. The pressure resistant stratum is formed by spirally winding, and overlapping, a belt or band the cross-section of which is in the form of an elongated S-shape having a groove in the bottom wall of each channel.

Abstract: A flexible conduit with a quadrangular hollow casing-shaped wire in the side wall of the conduit and extending the length of the conduit. The casing-shaped wire has at one side bent unjoined and overlapping extremities of the metal strip from which the wire is formed and is capable of receiving a hydraulic or electrical control line therein.

Abstract: A flexible conduit has an undulating liquid tight inner tube portion and layers of metal reinforcing wound around the tube. The layers include a burst resisting layer adjacent the tube, then traction and pressure resisting layers, and an outer sheath. The undulations in the interior of the tube can be filled with packing or the tube can be lined with a spiral strip to lessen resistance to fluid flow through the conduit.

Abstract: A composite flexible tube is disclosed. The central portion of the core of the tube is formed of a plurality of hollow elements dipsosed concentrically about the longitudinal axis of the tube.

Abstract: Pipe system for collecting petroleum from off-shore wells located at great depths comprises flexible pipes connecting well head to a float comprising an at least partially submerged caisson which contains air so as to maintain the flexible pipes under tension. Rigid pipes within the caisson lead from the flexible pipes to a discharge opening in a superstructure which projects above the surface of the sea.

Abstract: Apparatus for connecting at least one pipe-line situated on a sea-bed to a floating or semi-submersible platform which includes a vertical pipe-line section consisting of at least one flexible pipe arranged between a sinker resting on the sea-floor and an air-tank submerged at a sufficient depth to be protected from the action of the swell, the buoyancy of the air-tank being such that it maintains the flexible pipe section vertically under tension, the lower portion of the pipe-line of the section being connected to the pipe-line or lines situated on the sea-bed, while the upper end pipe-line of the section is connected to the submerged body of the platform by at least one additional pipe-line which is flexible along at least certain of its portions.