Composite component deployment configurations

Abstract

A riser system (202) comprises a riser (204) to be secured between a floating body (206) and a subsea location (209). The riser comprises a composite material formed of at least a matrix and one or more reinforcing elements embedded within the matrix. In use, the riser (204) comprises an upper portion (214) extending from the floating body (206) and having a region arranged to be in tension, a lower portion (216) extending from the subsea location (209) and having a region arranged to be in tension, and an intermediate portion (218) located between the upper and lower portions (214, 216) and having a region arranged to be in compression. A flow-line jumper (302, 402) configured to be secured between two subsea locations, a flow-line jumper arrangement comprising a flow-line jumper (302, 402) and a method of forming a flow-line jumper 302, 402 are also disclosed.

Claims

1. A riser system comprising a riser to be secured between a floating body and a subsea location, the riser comprising a composite material formed of at least a matrix and one or more reinforcing elements embedded within the matrix, wherein, in use, the riser comprises an upper portion extending from the floating body and having a region arranged to be always in tension, a lower portion extending from the subsea location and having a region arranged to be always in tension, and an intermediate portion located between the upper and lower portions and having a region arranged to be in compression; wherein, the riser comprises a pipe having a pipe wall comprising the composite material, wherein the pipe wall comprises or defines a local variation in construction of a local region of the intermediate portion to provide a local variation in a property of the pipe such that the riser bends in a predetermined manner such that the riser bends at a predetermined axial position or over a predetermined axial portion or bend in a predetermined plane; and wherein the local variation in construction comprises one or more of the following a local variation in the composite material, a local variation in the matrix, and a local variation in the one or more reinforcing elements.

2. The riser system according to claim 1, wherein the riser provides a predetermined tension in the upper or lower portions or a predetermined compression in the intermediate portion.

3. The riser system according to claim 2, wherein the density or geometry of the riser provide the predetermined tension in the upper or lower portions and the predetermined compression in the intermediate portion.

4. The riser system according to claim 1, wherein at least a portion of the riser defines a non-linear spatial arrangement to accommodate motion of the floating body relative to the subsea location.

5. The riser system according to claim 1, wherein the intermediate portion defines a non-linear spatial arrangement.

6. The riser system according to claim 1, wherein the upper portion of the riser extends generally linearly from the floating body towards the intermediate portion.

7. The riser system according to claim 1, wherein the lower portion of the riser extends generally linearly from the subsea location towards the intermediate portion.

8. The riser system according to claim 1, wherein a spatial arrangement of the riser comprises a point of inflection.

9. The riser system according to claim 1, comprising weights or buoyancy elements attached to the riser.

10. The riser system according to claim 1, wherein the riser is secured to a fluid port at the subsea location.

11. The riser system according to claim 1, wherein the composite material permits axial or bending strains of up to 6%, up to 4%, up to 2% or up to 1%.

12. The riser system according to claim 1, wherein the composite material is selected to ensure that a thermally induced strain in the riser for a predetermined temperature change constitutes a smaller proportion of a maximum permitted strain in the riser than for a steel riser.

13. The riser system according to claim 1, wherein the composite material is selected to ensure that a thermally induced strain in the riser for a temperature change of up to 500° C., a temperature change of up to 200° C., a temperature change of up to 100° C. or a temperature change of up to 80° C. constitutes a smaller proportion of a maximum permitted strain in the riser than for a steel riser.

14. The riser system according to claim 1, wherein the matrix comprises a polymer material.

15. The riser system according to claim 1, wherein the matrix comprises a thermoplastic material or a thermoset material.

16. The riser system according to claim 1, wherein the matrix comprises at least one of a polyaryl ether ketone, a polyaryl ketone, a polyether ketone (PEK), a polyether ether ketone (PEEK), a polycarbonate, a polymeric resin and an epoxy resin.

17. The riser system according to claim 1, wherein the reinforcing elements comprise at least one of fibres, strands, filaments and nanotubes.

18. The riser system according to claim 1, wherein the reinforcing elements comprise at least one of polymeric element, aramid element, non-polymeric element, carbon elements, glass elements and basalt elements.

19. The riser system according to claim 1, wherein the riser system comprises a device for providing additional axial compliance to that provided by the riser connected between the floating body and the subsea location.

20. The riser system according to claim 19, comprising a compliant bellows connected between the floating body and the subsea location.

21. The riser system according to claim 1, wherein the riser comprises one or more fibre optic strain sensors.

22. The riser system according to claim 1, wherein the riser comprises the upper portion extending from the floating body and having the region arranged to be always in tension, the lower portion extending from the subsea location and having the region arranged to be always in tension, and the intermediate portion located between the upper and lower portions and having the region arranged to be in compression, in use under static load conditions.

23. The riser system according to claim 1, wherein the local variation in construction provides a local variation in a property of the pipe so as to facilitate bending in localised regions such that, in use, the riser defines a non-linear spatial arrangement, such that the composite material and the non-linear spatial arrangement accommodate motion of the floating body relative to the subsea location.

24. A riser system comprising a riser to be secured between a floating body and a subsea location, the riser comprising a composite material formed of at least a matrix and one or more reinforcing elements embedded within the matrix, said riser, in use, defining a non-linear spatial arrangement, such that the composite material and the non-linear spatial arrangement accommodate motion of the floating body relative to the subsea location; and the riser comprises a pipe having a pipe wall comprising the composite material, wherein the pipe wall comprises or defines a local variation in construction of a local region of the intermediate portion to provide a local variation in a property of the pipe such that the riser bends in a predetermined manner such that the riser bends at a predetermined axial position or over a predetermined axial portion or bend in a predetermined plane, wherein the local variation in construction comprises one or more of the following, a local variation in the composite material, a local variation in the matrix, and a local variation in the one or more reinforcing elements.

25. A flow-line jumper for securing between two subsea locations, said jumper comprising a composite material formed of at least a matrix and one or more reinforcing elements embedded within the matrix and said flow-line jumper defining a non-linear spatial arrangement configured to provide compliance for the jumper between the two subsea locations; and a riser comprises a pipe having a pipe wall comprising a composite material, wherein the pipe wall comprises or defines a local variation in construction of a local region of the intermediate portion to provide a local variation in a property of the pipe such that the flow-line jumper bends in a predetermined manner such that the riser bends at a predetermined axial position or over a predetermined axial portion or bend in a predetermined plane, wherein the local variation in construction comprises one or more of the following, a local variation in the composite material, a local variation in the matrix, and a local variation in the one or more reinforcing elements.

26. The flow-line jumper according to claim 25, wherein the flow-line jumper has a non-linear portion.

27. The flow-line jumper according to claim 25, wherein the flow-line jumper defines at least one of a pig-tail shape, an omega shape, a coil, a helix and a spiral.

28. A method for providing a riser between a floating body and a subsea location, comprising: connecting a riser between the floating body and a subsea location, wherein the riser comprises a composite material formed of at least a matrix and one or more reinforcing elements embedded within the matrix, wherein the riser comprises a pipe having a pipe wall comprising the composite material, wherein the pipe wall comprises or defines a local variation in construction of local region of the intermediate portion to provide a local variation in a property of the pipe such that the riser bends in a predetermined manner such that the riser bends at a predetermined axial position or over a predetermined axial portion or bend in a predetermined plane, wherein the local variation in construction comprises one or more of the following, a local variation in the composite material, a local variation in the matrix, and a local variation in the one or more reinforcing elements; configuring at least a region of an upper portion of the riser extending from the floating body to be always in tension; configuring at least a region of a lower portion of the riser extending from the subsea location to be always in tension; and configuring at least a region of an intermediate portion of the riser located between the upper and lower portions to be in compression.

Description

BRIEF DESCRIPTION OF THE DRAWINGS

(1) The present invention will now be described by way of non-limiting example only with reference to the accompanying drawings of which:

(2) FIG. 1 is a schematic view of a riser system;

(3) FIG. 2 is a schematic view of an alternative riser system;

(4) FIG. 3(a) is a schematic view of a further riser system;

(5) FIG. 3(b) is a schematic view of the riser system of FIG. 3(a) with weights and buoyancy elements attached to a riser of the riser system;

(6) FIG. 4(a) is a schematic front elevation of a flow-line jumper;

(7) FIG. 4(b) is a schematic end elevation of the flow-line jumper of FIG. 4(a); and

(8) FIG. 5 is a schematic view of a further flow-line jumper.

DETAILED DESCRIPTION OF THE DRAWINGS

(9) With reference initially to FIG. 1, there is shown a riser system generally designated 2 comprising a composite riser 4 secured between a vessel 6 floating on the sea surface 7 and a fixed tree arrangement 8 at a subsea location 9 on the seabed 10. The riser 4 extends substantially vertically between the vessel 6 and the tree arrangement 8. The length, weight and/or buoyancy of the riser 4 are selected to provide a predetermined tension in the riser 4 for a given depth of water.

(10) The riser 4 comprises a composite material formed of a matrix of polyether ether ketone (PEEK) and carbon fibre reinforcing elements (not shown) embedded within the PEEK matrix. The composite material of the riser 4 comprises a plurality of axially oriented carbon fibre reinforcing elements. As a result of this composite structure, the particular riser 4 shown in FIG. 1 may permit large axial or bending strains, for example, axial or bending strains of up to 2% or more. This compares with typical maximum permissible axial or bending strains of a steel riser which may be in the region of approximately 0.1%. Thus, the composite riser 4 offers significantly more compliance by virtue of its material properties alone compared with a conventional steel riser. Accordingly, the material properties of the riser 4 compensate for the heave motion of the floating body 6 relative to the tree arrangement 8, thus allowing attachment of the riser 4 between the vessel 6 and the tree arrangement 8 without the need for any active heave compensation mechanisms such as hydraulic rams or the like.

(11) The material properties of the riser 4 also ensure that a thermally induced strain in the riser 4 for a given temperature change constitutes a significantly smaller proportion of the maximum permitted strain in the riser 4 than for a conventional steel riser. For example, for a temperature change of approximately 80° C., the thermally induced strain in the riser 4 constitutes a significantly smaller proportion of the maximum permitted strain in the riser 4 than for a conventional steel riser. The riser 4 thus has a greater permissible strain range once thermally induced strain changes are taken into account compared with a steel riser.

(12) Referring now to FIG. 2, there is shown an alternative riser system generally designated 102 comprising a composite riser generally designated 104 configured to be secured between a body such as a vessel 106 floating on the sea surface 107 and a fixed tree arrangement 108 at subsea location 109 on the seabed 110. The riser 104 further comprises a bellows 112 which are connected to the vessel 106 by an upper riser portion 114 and are connected to the tree arrangement 108 by a lower riser portion 116. The riser 104 extends substantially vertically between the vessel 106 and the tree arrangement 8. The length, weight and/or buoyancy of the riser 104 and the bellows 112 are selected to provide a predetermined tension in the riser 104 for a given depth of water.

(13) The bellows 112 provide additional compliance to further mitigate the effects of heave motion of the floating body 106 relative to the tree arrangement 108 if necessary in, for example, heavy sea conditions. In all other respects the riser system 102 of FIG. 2 is identical to the riser system 2 of FIG. 1.

(14) FIG. 3(a) shows a further riser system generally designated 202 comprising a composite riser 204 secured between a vessel 206 floating on the sea surface 207 and a fixed tree arrangement 208 at a subsea location 209 on the seabed 210. The length of the riser 204 is greater than the depth of the water so that the riser 204 assumes a non-linear spatial arrangement.

(15) The riser 204 comprises a composite material formed of a matrix of polyether ether ketone (PEEK) and carbon fibre reinforcing elements (not shown) embedded within the PEEK matrix. The composite material of the riser 204 comprises a plurality of axially oriented carbon fibre reinforcing elements.

(16) As a result of this composite structure, the particular riser 204 shown in FIG. 3(a) may permit large axial or bending strains, for example, axial or bending strains of up to 2% or more. This compares with typical maximum permissible axial or bending strains of a steel riser which may be in the region of approximately 0.1%. Thus, the composite riser 204 offers significantly more compliance by virtue of its material properties alone compared with a conventional steel riser.

(17) Thus, the material properties of the composite riser 204 may serve to increase the compliance provided by the non-linear spatial arrangement of the riser 204. The combined compliance of the riser system 202 compensates for the heave motion of the floating body 206 relative to the tree arrangement 208, thus allowing attachment of the riser 204 between the vessel 206 and the tree arrangement 208 without any active heave compensation mechanisms such as hydraulic rams or the like.

(18) The material properties of the composite riser 204 also ensure that a thermally induced strain in the riser 204 for a given temperature change constitutes a significantly smaller proportion of the maximum permitted strain in the riser 204 than for a conventional steel riser. For example, for a temperature change of approximately 80° C., the thermally induced strain in the riser 204 constitutes a significantly smaller proportion of the maximum permitted strain in the riser 204 than for a conventional steel riser. The riser 204 thus has a greater permissible strain range once thermally induced strain changes are taken into account compared with a steel riser.

(19) The riser 204 comprises an upper portion 214 which extends generally downwardly from the vessel 206, a lower portion 216 which extends generally upwardly from the tree arrangement 208 and, an intermediate portion 218 which extends between the upper and lower portions 214, 216.

(20) The riser system 202 is configured such that the upper portion 214 of the riser 204 is in tension, the lower portion 216 of the riser 204 is in tension and the intermediate portion 218 of the riser 204 is in compression. The configuration of the riser 204 is selected to provide a desired tension in the upper and lower portions. In particular, the density and geometry of the riser are selected to provide a predetermined tension in the upper and lower portions 214, 216.

(21) The composite riser 204 is much lighter than a conventional steel riser with the result that the composite riser 204 is closer to neutral buoyancy in sea water than a steel riser. Accordingly, the use of a composite material for the riser 204 may mitigate or eliminate the need to attach weights and/or buoyancy elements to the riser 204 to provide the appropriate tension in the upper and lower portions 214, 216 of the riser 204 and the appropriate compression in the intermediate portion 218 of the riser 204. However, where necessary, as shown in FIG. 3(b), the riser system 202 may further comprise weights 220 which serve to tension the upper portion 214 of the riser 204 to ensure that the upper portion 214 extends generally vertically downwardly from the vessel 206. The riser system 202 may further comprise buoyancy elements 222 which serve to tension the lower portion 216 of the riser 204 to ensure that the lower portion 216 extends generally vertically upwardly from the tree arrangement 208. As a result of the combined effect of the weights 220 and the buoyancy elements 222, the intermediate portion 218 adopts a predetermined desired “S”-shaped spatial arrangement.

(22) FIG. 4 shows a composite “pig-tail” shaped subsea flow-line jumper generally designated 302 for connection between a first subsea fluid port 304 for connection to a riser 305 and a second subsea fluid port 306 for connection to a fluid conduit 307. By virtue of its non-linear geometry, the jumper 302 permits a relatively large movement of the jumper ends 308 and 310 with respect to one another in a compact space envelope.

(23) The jumper 302 comprises a composite material formed of a matrix of polyether ether ketone (PEEK) and carbon fibre reinforcing elements (not shown) embedded within the PEEK matrix. The composite material of the jumper 302 comprises a plurality of axially oriented carbon fibre reinforcing elements. As a result of this composite structure, the particular jumper 302 shown in FIG. 4 may permit large axial or bending strains, for example, axial or bending strains of up to 2% or more. This compares with typical maximum permissible axial or bending strains of a steel jumper which may be in the region of approximately 0.1%. Thus, the composite jumper 302 offers significantly more compliance by virtue of its material properties alone compared with a conventional steel jumper. Thus, the material properties of the composite jumper 302 serve to increase the compliance provided by the non-linear spatial arrangement of the jumper 302.

(24) The material properties of the composite jumper 302 also ensure that a thermally induced strain in the jumper 302 for a given temperature change constitutes a significantly smaller proportion of the maximum permitted strain in the jumper 302 than for a conventional steel jumper. For example, for a temperature change of approximately 80° C., the thermally induced strain in the jumper 302 constitutes a significantly smaller proportion of the maximum permitted strain in the jumper 302 than for a conventional steel jumper.

(25) The material properties of the composite jumper 302 provide enhanced immunity to damage such as that caused by buckling under dynamic load conditions. The material properties of the composite jumper 302 permit manufacturing tolerances to be relaxed compared with manufacturing tolerances when using a conventional material such as steel or the like. The material properties of the composite jumper 302 also ease installation. This may be particularly important in a subsea environment where manipulation of the jumper 302 between the two fluid ports 304, 306 and securing of the jumper 302 at the two fluid ports 304, 306 may be challenging. In addition, the

(26) The use of thermoplastic PEEK matrix also permits the jumper 302 to be manufactured by first forming a fluid conduit, for example a substantially linear fluid conduit, and subsequently forming the fluid conduit into the pig-tail spatial arrangement shown in FIG. 4. This results in an integrally formed composite jumper 302 which may have fewer, more gradual bends. This may reduce or suppress hydrate build up as a result of a flow of hydrocarbon fluids through the jumper. This may also present less of a restriction for hydrate removal operations such as pigging operations. thus facilitating removal of hydrate build by pigging. Other non-linear composite jumper spatial arrangements are also possible. For example, FIG. 5 shows an “omega”—shaped composite jumper 402 which only differs from the “pig-tail” shaped composite jumper 302 of FIG. 4 in the exact non-linear spatial arrangement thereof

(27) One skilled in the art will understand that various other riser and jumper spatial arrangements are possible without departing from the scope of the present invention. For example, coiled spatial arrangements such as helical or spiral spatial arrangements may be used to provide compliant risers and jumpers.