Marine riser

1. A marine riser comprising:

at least two riser sections which are connected in an end-to-end relationship, the at least two riser sections being configured to extend between a subsea installation and a suspension device arranged above the subsea installation, at least one of the at least two riser sections comprising at least one pipe which comprises a heat exchanger,

wherein,

the heat exchanger comprises a support casing and a plurality of radially extending fins which extend radially from the support casing, the heat exchanger being configured to be assembled on a portion of the at least one pipe.

2. The marine riser as recited in claim 1 , wherein the heat exchanger is configured to be releasably connected to the at least one pipe.

3. The marine riser as recited in claim 1 , wherein the radially extending fins are configured to extend in an axial direction along the support casing.

4. The marine riser as recited in claim 3 , wherein the radially extending fins are integral with the support casing.

5. The marine riser as recited in claim 1 , wherein the support casing comprises a tubular body.

6. The marine riser as recited in claim 5 , wherein,

the support casing comprises two support casing halves and a connection device, and

the two casing halves are configured to be interconnectable via the connection device to form the tubular body.

7. The marine riser as recited in claim 1 , wherein the heat exchanger further comprises a covering element which is arranged circumferentially around radially outer ends of the plurality of radially extending fins.

8. The marine riser as recited in claim 1 , further comprising a second heat exchanger comprising a plurality of branch pipes which are fluidly connected to the at least one pipe.

9. The marine riser as recited in claim 8 , wherein the heat exchanger is connected to a part of the plurality of branch pipes of the second heat exchanger.

10. The marine riser as recited in claim 8 , wherein,

the at least one of the at least two riser sections is a first riser section which is located closer to the subsea installation than remaining riser sections of the at least two riser sections, and

at least one of the heat exchanger and the second heat exchanger is attached to at least one of the at least one pipe of the first riser section.

11. The marine riser as recited in claim 10 , wherein,

the at least one pipe of the first riser section comprises a metal material, and

the at least one pipe of the remaining riser sections of the at least two riser sections comprises a composite material.

12. The marine riser as recited in claim 11 , wherein,

the at least one pipe of the first riser section comprises aluminum or steel, and

the at least one pipe of the remaining riser sections of the at least two riser sections comprises a carbon-reinforced polymer.

13. The marine riser as recited in claim 12 , wherein the carbon-reinforced polymer is epoxy.

14. The marine riser as recited in claim 1 , wherein,

the at least one pipe includes a main pipe and a kill-and-choke line, and

each of the at least two riser sections comprises each of the main pipe and the kill-and-choke line.

15. A marine riser comprising:

at least two riser sections which are connected in an end-to-end relationship, the at least two riser sections being configured to extend between a subsea installation and a suspension device arranged above the subsea installation, at least one of the at least two riser sections comprising at least one pipe which comprises a heat exchanger,

wherein,

the heat exchanger comprises a support casing which is configured to be assembled on a portion of the at least one pipe,

the support casing comprises a tubular body,

the support casing comprises two support casing halves and a connection device, and

the two casing halves are configured to be interconnectable via the connection device to form the tubular body.

16. The marine riser as recited in claim 15 , wherein the heat exchanger is configured to be releasably connected to the at least one pipe.

17. A marine riser comprising:

at least two riser sections which are connected in an end-to-end relationship, the at least two riser sections being configured to extend between a subsea installation and a suspension device arranged above the subsea installation, at least one of the at least two riser sections comprising at least one pipe which comprises a first heat exchanger, a second heat exchanger, an uppermost end, and a lowermost end,

wherein,

the second heat exchanger comprises a plurality of branch pipes, and

each of the plurality of branch pipes is fluidly connected to the uppermost end and to the lowermost end of the at least one pipe.

18. The marine riser as recited in claim 17 , wherein the first heat exchanger is connected to a part of the plurality of branch pipes of the second heat exchanger.

19. The marine riser as recited in claim 17 , wherein,

the at least one of the at least two riser sections is a first riser section which is located closer to the subsea installation than remaining riser sections of the at least two riser sections, and

at least one of the first heat exchanger and the second heat exchanger is attached to at least one of the at least one pipe of the first riser section.

20. The marine riser as recited in claim 19 , wherein,

the at least one pipe of the first riser section comprises a metal material, and

the at least one pipe of the remaining riser sections of the at least two riser sections comprises a composite material.

21. The marine riser as recited in claim 20 , wherein,

the at least one pipe of the first riser section comprises aluminum or steel, and

the at least one pipe of the remaining riser sections of the at least two riser sections comprises a carbon-reinforced polymer.

22. The marine riser as recited in claim 21 , wherein the carbon-reinforced polymer is epoxy.

23. The marine riser as recited in claim 17 , wherein,

the at least one pipe includes a main pipe and a kill-and-choke line, and

each of the at least two riser sections comprises each of the main pipe and the kill-and-choke line.