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1. WO2011027154 - METHOD OF TESTING AN UNBONDED FLEXIBLE PIPELINE

Note: Text based on automatic Optical Character Recognition processes. Please use the PDF version for legal matters

[ EN ]

Claims

1. A method of testing an unbonded flexible pipeline comprising a polymer pressure sheath, the method comprising at least the steps of:

(a) transmitting an electromagnetic signal along the polymer pressure sheath;

(b) seeking one or more reflected signals; and

(c) analysing the or each reflected signal to determine one or more characteristics of the electrical permittivity of the polymer pressure sheath.

2. A method as claimed in claim 1 wherein the pipeline is an underwater pipeline, preferably a hydrocarbon conductor.

3. A method as claimed in claim 1 or claim 2 wherein the pipeline further comprises one or more metallic armour layers and a metallic carcass layer, preferably on either side of the polymer pressure sheath.

4. A method as claimed in any one of claims 1 to 3 wherein the polymer pressure sheath is a polyamide, preferably including nylon.

5. A method as claimed in claim 4 wherein the polymer pressure sheath is Rilsan (RTM) PA-11.

6. A method as claimed in any one of the preceding claims wherein the electromagnetic signal is generated by an electrical signal comprising one or more voltage pulses.

7. A method as claimed in any one of the preceding claims wherein the electromagnetic signal is generated by an electrical signal comprising one or more frequency swept sine waves.

8. A method as claimed in any one of the preceding claims wherein the method uses time domain reflectometry.

9. A method as claimed in claim 8 based on claim 7 wherein the method uses frequency domain time domain reflectometry.

10. A method as claimed in any one of claims 6 to 9 wherein the frequency of the electrical signal is in the range 1 MHz to 2 GHz, preferably in the range 100 MHz to 2 GHz.

11. A method as claimed in any one of claims 6 to 10 wherein the wavelength of the electrical signal is smaller than a length of the pipeline being tested.

12. A method as claimed in any one of the preceding claims comprising the further step of propagating the wavelength of the electromagnetic signal to extend the length of the pipeline being tested.

13. A method as claimed in any one of the preceding claims wherein steps (a) and (b) are carried out from one end of the pipeline.

14. A method as claimed in any one of claims 1 to 12 being a non-destructive method of testing an in situ flexible pipeline.

15. A method as claimed in claim 14 wherein step (b) is carried out in the pipeline, optionally using a pig.

16. A method as claimed in claim 14 or claim 15 wherein at least a

portion of the flexible pipeline comprises two pipes and a flange

connection, and the transmission of the electromagnetic signal of step (a) is carried out passed the flange connection.

17. A method as claimed in any one of the preceding claims wherein the or each reflected signal is interpreted by comparison against the corrected inherent viscosity of the polymer pressure sheath.

18. A method of testing as claimed in any one of the preceding claims for testing the ageing, degradation or both of the polymer pressure sheath.

9. A system for testing an unbonded flexible pipeline comprising a polymer pressure sheath, the system comprising at least:

(a) a transmitter for generating an electromagnetic signal along the polymer pressure sheath;

(b) a monitor for seeking one or more reflected signals; and

(c) an analyser for analysing the or each reflected signal to determine one or more characteristics of the electrical permittivity of the polymer pressure sheath.