Unbonded flexible pipe and an end-fitting

Patent metadata

Field	Value
Publication number	US-11300237-B2
Application number	US-201816485905-A
Country	US
Kind code	B2
Filing date	Feb 19, 2018
Priority date	Feb 20, 2017
Publication date	Apr 12, 2022
Grant date	Apr 12, 2022

Abstract

An assembly comprising an end-fitting and an unbonded flexible pipe comprising several layers. The unbonded flexible pipe has an end-part entering the end-fitting at the front end and the layers of the unbonded flexible pipe being terminated in the end-fitting. The unbonded flexible pipe further comprises a first electrically conductive layer and a second electrically conductive layer, where the first electrically conductive layer is electrically insulated from the second electrically conductive layer. The end-fitting comprises a first electric zone electrically connected with the first electrically conductive layer, and a second electric zone electrically connected with the second electrically conductive layer, the first electric zone is electrically separated from the second electric zone, and the end-fitting comprises a third electric zone, the third electric zone being electrically separated from first electric zone and the second electric zone.

First claim

What is claimed is:

1. An assembly comprising an end-fitting with a first-end and a second-end and a through-going opening having a center axis between the first-end and the second-end, and an unbonded flexible pipe comprising several layers and having a center axis along its length, said center axis of the unbonded flexible pipe being substantially coinciding with the center axis of the end-fitting for the part of the unbonded flexible pipe arranged in the end-fitting,
said unbonded flexible pipe, having an end-part entering the end-fitting at the first-end and the layers of the unbonded flexible pipe being terminated in the end-fitting between the first-end and the second-end,
said unbonded flexible pipe further comprises a first electrically conductive layer and a second electrically conductive layer, said first electrically conductive layer being electrically insulated from the second electrically conductive layer, and
the end-fitting comprises a first electric zone electrically connected with the first electrically conductive layer, and a second electric zone electrically connected with the second electrically conductive layer, said first electric zone being electrically separated from the second electric zone, wherein the end-fitting comprises a third electric zone, said third electric zone being electrically separated from first electric zone and the second electric zone, wherein
said first electric zone and said second electric zone are arranged along the length of and concentrically in respect of the center axis and at least a part of said third electric zone is located closer to the second end of the end-fitting than the first electric zone and the second electric zone, and
the first electrically conductive layer and the second electrically conductive layer are connected with a source for electric power via the first electric zone and the second electric zone of the end-fitting, the applied electric power source is configured for being floating.

2. An assembly according to claim 1 , wherein the first electrically conductive layer and the second electrically conductive layer of the unbonded flexible pipe are arranged substantially concentrically in respect of the center axis.

3. An assembly according to claim 1 , wherein the end-fitting comprises an outer cover surrounding and being substantially co-axially with at least a part of the first electric zone and/or the second electric zone, said outer cover being of non-conductive material.

4. An assembly according to claim 1 , wherein the end-fitting comprises an outer cover surrounding and being substantially co-axially with at least a part of the first electric zone and/or the second electric zone, said outer cover being of electrically conductive material and connected with ground.

5. An assembly according to claim 1 , wherein the end-fitting comprises an outer cover surrounding and being substantially co-axially with at least a part of the first electric zone and/or the second electric zone, said outer cover being of electrically conductive material and connected to the third electric zone.

6. An assembly according to claim 5 , wherein a void is formed between the outer cover and at least a part of the first electric zone and/or the second electric zone, said void being filled with an electrically insulating material.

7. An assembly according to claim 1 , wherein the unbonded flexible pipe from the inside and outwards comprises a carcass, an internal pressure sheath, at least one pressure armor, at least one tensile armor and optionally an outer sheath.

8. An assembly according to claim 1 , wherein the unbonded flexible pipe further comprises one or more intermediate layers.

9. An assembly according to claim 1 , wherein the unbonded flexible pipe comprises at least one thermal insulating layer.

10. An assembly according to claim 1 , wherein the first electrically conductive layer is a carcass.

11. An assembly according to claim 1 , wherein the first electrically conductive layer is a pressure armor.

12. An assembly according to claim 1 , wherein the second electrically conductive layer is a pressure armor.

13. An assembly according to claim 1 , wherein the second electrically conductive layer is a tensile armor.

14. An assembly according to claim 1 , wherein the insulation between the first electrically conductive layer and the second electrically conductive layer is constituted at least partly by the internal pressure sheath.

15. An assembly according to claim 1 , wherein the applied voltage is in the range 100 V to 10 kV.

Assignees

• Nat Oilwell Vareo Denmark I/S
• Nat Oilwell Varco Denmark Is

Inventors

• Holst Thorsten
• Larsen Tom
• Straarup Anders

Classifications

• F16L11/082

  two layers · CPC title

• F16L33/28

  for hoses with one end terminating in a radial flange or collar · CPC title

• F16L33/01

  specially adapted for hoses having a multi-layer wall · CPC title

• F16L53/37 Primary

  the heating current flowing directly through the pipe to be heated · CPC title