Nkt Flexibles I/s

Nkt Flexible I/s

National Oilwell Varco Denmark I/s

Jan Christian Rytter

Kristian Glejbol

Jakob Wedel-Heinen

Kristian Glejbøl

Kristian Glejb&oslash;l

A flexible pipe for transporting a fluid in a marine environment. The pipe comprises a liner for confining the fluid, an armoring layer surrounding the liner, and an outer protective sheath surrounding the armoring layer and allowing radial expansion and contraction of the armoring layers. The outer protective sheath comprises at least two protective layers of helically wound composite wires with essentially opposite winding angles and locally held together, providing a relatively flexible yet fixed structure of the outer sheath. The outer sheath is held together in an array of discrete spots or along linear or curved paths. Flexibility is maintained because the stiffness in shear in the wires of adjacent protective layers may be made much larger in areas being locally held together than outside these areas. This allows a change of angles between the wires of two adjacent layers of the outer protective sheath during elongation or shortening of the pipe.

Flexible pipe with a permeable outer sheath and a method of its manufacturing

A flexible, typically un-bonded, armored pipe, and a method manufacturing a flexible pipe. The pipe has a center axis and comprises an inner liner surrounded by a radial armoring and an axial armoring, the radial and axial armoring each comprising at least one armoring layer of armoring profiles wound with winding angles &#x3b1;relative to the center axis. The winding angle of the innermost armoring layer &#x3b1;is larger than the winding angle of the outermost armoring layer &#x3b1;. The outer radial armoring layer has sufficient strength and flexibility to prevent prohibitively large radial deformations of underlying axial armoring layers without considerably increasing the radial contact pressure on underlying axial armoring layer. At least one fibrous layer, comprising at least two fibrous cords wound on an underlying layer, surrounds the outermost armoring layer. The flexible pipe is useful in terrestrial and/or subsea transport of fluids at elevated temperature and/or pressures.

Flexible pipe, its manufacture and use

A pipe structure comprising a length of a flexible pipe connected to an end fitting, the flexible pipe comprising an armour layer and an underlying pipe layer the armour layer, the underlying pipe layer having an outer surface around which armouring wires of an armouring layer are helically wound. The pipe structure provides a coupling between a flexible pipe comprising armouring wires and an end fitting, the coupling exerting a relatively low bending or flexure strain on the wires during normal operation of the flexible pipe. The transition path of an armouring wire between the flexible pipe and the end fitting comprises a straight-line-section between a wire-pipe-exit-point where the wire extends away from its underlying pipe layer and a straight-line-end-point on a support unit of the end fitting where the armouring wire in question has its first tangential point of contact. This has the advantage that in a loaded situation where the armouring wires will elongate elastically leading to a change in the helical angle of the armouring wires, the pipe structure will experience a slight twist and a controlled bending of the armouring wires on the surface of the support unit (due to a possible change in the base point of contact of the armouring wire with the support unit induced by the change of helical angle), thereby avoiding substantial bending of the individual armouring wires, which is of particular importance when the armouring wires are formed of a composite material. The pipe structure may be used in flexible pipes for the off shore transport of fluids (e.g. oil).

Flexible pipe connected to an end fitting

An armoured flexible pipe has an inner liner () surrounded by a pressure armour () that is surrounded by a tensile armour (). The pressure armour () is constructed from a number of profiles () which may engage with each other. In order to obtain optimum functionality, the profiles are shaped as X profiles () which are kept together with another type of profile, e.g. C or T type profiles. In one embodiment, the X profiles have an open channel (). In this way gas or liquid, such as rinsing fluid, may be pumped through the armour layer, from one end of the pipe to the other end. In particular, the armoured flexible pipe is useful for conveying fluids such as water, ammonia, hydrocarbons, etc.

Armoured flexible pipe and use of same

A flexible, armoured pipe has an impermeable inner liner (), which is surrounded by at least two reinforcement layers (). Between the reinforcement layers an impermeable membrane () is provided, which ensures that fluids do not permeate into the inner reinforcement layers () from the pipe's outer reinforcement layers (). The outer layers are not isolated from influence from the surrounding environment. Moreover, the outer layers (traction reinforcement layers) are protected against the damaging effect of gases, which are diffused out through the flexible pipe. On the outside of the outer traction reinforcement layers () a layer () can be applied, which is easily permeated by the surroundings, and which protects the traction reinforcement layer against mechanical influences. In this way it is ensured that the pressure reinforcement can absorb forces both from inner as well as outer pressure.

Armored, flexible pipe and use of same

Flexible, armored pipes and methods of using the same are disclosed. In an exemplary embodiment, the flexible, armored pipe includes an inner liner which is surrounded by a pressure armor. The inner liner may be built-up by joining together profiles that have a number of recesses. In one embodiment, the profiles are configured as K-profiles, which have recesses that are arranged in adjoining surfaces of the profile. When the profiles are brought together, the recesses form a cavity in which a locking element can be inserted, the function of which is to prevent displacement of the K-profiles at right-angles to the axial direction of the pipe when exposed to axial, compressive forces. The locking element can be I-shaped, circular or configured as a wire with a C-shaped cross-section. The locking element can also be made either of a rigid or an elastic, deformable material. With a C-shaped locking element, the whole of the cavity, which is formed by the recesses, is not filled out. A channel is thereby formed through which undesired fluids can be led away or through which cleaning fluids can be introduced.

Growing community of inventors

Copenhagen, Denmark

Jan Christian Rytter