Thermal insulation of flexible pipes

1. Flexible pipe body for a flexible pipe for transporting production fluids such as oil, gas and water from a sub-sea location, said pipe body comprising:

an internal pressure sheath constructed to withstand deep water environments;

at least one insulating layer comprising a mesh layer comprising a plurality of pockets;

an outer sheath constructed to withstand deep water environments; and

an insulating aerogel material disposed in a plurality of said pockets, wherein the insulating aerogel material has a thermal conductivity of 0.009 to 0.022 w/mk, and wherein the at least one insulating layer is provided between the internal pressure sheath and the outer sheath;

wherein the pipe body is configured for sub-sea use for transporting production fluids from a sub-sea location and constructed to withstand operating conditions in deep water environments.

2. The flexible pipe body as claimed in claim 1 , further comprising:

said mesh layer comprises woven filaments, a plurality of holes between the filaments defining respective locations of said pockets.

3. The flexible pipe body as claimed in claim 2 , wherein said filaments comprise metal wires.

4. The flexible pipe body as claimed in claim 1 , wherein said mesh layer comprises a web layer comprising a plurality of blind or through holes preformed in the web.

5. The flexible pipe body as claimed in claim 4 , wherein the holes are preformed in a predetermined pattern.

6. The flexible pipe body as claimed in claim 4 , wherein said web is a metal sheet.

7. The flexible pipe body as claimed in claim 1 , wherein said insulating layer comprises a mesh tape helically wrapped over the internal pressure sheath.

8. The flexible pipe body as claimed in claim 7 wherein said tape is wrapped directly onto an outer surface of at least one intermediate layer located radially between the internal pressure sheath and the outer sheath.

9. The flexible pipe body as claimed in claim 1 , wherein said insulating layer further comprises an inner extruded layer and an outer extruded layer, said mesh layer being disposed between the inner and outer extruded layers.

10. The flexible pipe body as claimed in claim 9 , further comprising:

a metal layer between said mesh layer and the inner and/or outer extruded layer.

11. The flexible pipe body as claimed in claim 10 , wherein said metal layer comprises a thin layer of metal tape helically wrapped around the internal pressure sheath.

12. The flexible pipe body as claimed in claim 1 , wherein the internal pressure sheath comprises a barrier layer or liner.

13. A flexible pipe comprising the flexible pipe body as claimed in claim 1 , further comprising:

two end fittings each located at a respective one of two ends of the pipe body wherein said insulating layer comprises a continuous layer extending between the end fittings.

14. A riser, flowline or jumper comprising the flexible pipe as claimed in claim 13 .

15. A method of transporting a production fluid such as oil, gas and water from a sub-sea location comprising:

providing a flexible pipe comprising an internal pressure sheath constructed to withstand deep water environments, at least one insulating layer comprising a mesh layer comprising a plurality of pockets, an outer sheath constructed to withstand deep water environments and an insulating aerogel material disposed in a plurality of said pockets, wherein the insulating aerogel material has a thermal conductivity of 0.009 to 0.022 w/mk and wherein the at least one insulating layer is provided between the internal pressure sheath and the outer sheath and wherein said mesh layer comprises a web layer comprising a plurality of blind or through holes preformed in the web;

placing the flexible pipe in a sub-sea location; and

transporting a fluid through the flexible pipe.