Wellbore monitoring system using strain sensitive optical fiber cable package

Patent metadata

Field	Value
Publication number	US-10215016-B2
Application number	US-201515026873-A
Country	US
Kind code	B2
Filing date	Mar 10, 2015
Priority date	Mar 10, 2015
Publication date	Feb 26, 2019
Grant date	Feb 26, 2019

Abstract

A distributed acoustic sensing cable package having a polymer composite extruded over an optical waveguide to encase the waveguide and to form a crystalline matrix layer acoustically coupled to the waveguide. The crystalline matrix includes reinforcement fibers to further enhance transmission of a cable strain to the optical waveguide. During manufacture of the cable, the polymer composite may be extruded over the optical waveguide and subsequently subjected to heat treatment to increase the crystallinity of the polymer composite and increase the elastic modulus. Both axial and radial strain fields are effectively interact with cased fiber waveguide for producing measurable phase shift signal for distributed acoustic noise detection.

First claim

The invention claimed is:

1. A wellbore monitoring system comprising:
an elongated tubular member disposed in a wellbore;
an optical cable deployed along a length of the elongated tubular member, the optical cable comprising:
an optical waveguide disposed along an axis of the cable;
a polymer composite extruded over the optical waveguide to directly encase the optical waveguide in the polymer composite and acoustically couple the optical waveguide to the polymer composite, wherein the polymer composite includes reinforcement fibers embedded throughout the polymer composite; and
a protective sheath disposed around the polymer composite, an acoustic impedance of the protective sheath being lower than an acoustic impedance of the optical waveguide with the polymer composite encasing the optical waveguide;

a light source in optical communication with the optical cable; and
an interrogator in optical communication with the optical cable.

2. The system of claim 1 , wherein the polymer composite is selected from the group consisting of polyetheretherketone (PEEK), polyimide (PI), polyphenylene sulfide (PPS), polyetherketone (PEEK), carbon fiber doped polyetherketone (c-PEEK) and metal-wire enhanced polyetherketone (m-PEEK), polyaryletherketone (PAEK) and combinations thereof.

3. The system of claim 1 , further comprising at least two optical cables deployed in the wellbore wherein the interrogator system comprises wavelength division multiplexing (DWDM) switch and an optical coupler in optical communication with the two optical cables.

4. The system of claim 3 , wherein at least one optical cable is deployed outside a casing string and at least one optical cable is deployed inside the casing string.

5. The system of claim 1 , wherein the light source is tunable laser source from 1490 nm to 1610 nm.

6. The system of claim 1 , wherein the polymer composite enhances a sensitivity of the optical waveguide to a cable elongation effect.

7. The system of claim 6 , wherein the reinforcement fibers are a multiplicity of chopped fibers embedded in the polymer composite and selected from the group consisting of carbon fibers, ceramic fibers, glass fibers, synthetic fibers, and metal fibers.

8. The system of claim 7 , wherein the ratio of reinforced fibers in the polymer composite is from 10% to 70%.

9. The system of claim 6 , wherein the reinforcement fibers comprise a plurality of elongated reinforcement fibers extending along the axis and embedded within the polymer composite.

10. The system of claim 1 , wherein the polymer composite has a crystallinity percentage ranging from 20% to 70% by volume.

11. The system of claim 1 , wherein the polymer composite comprises at least a first polymer and a second polymer different from the first polymer in elastic modulus and glass transition temperature.

12. The system of claim 11 , wherein the first polymer is characterized by a glass transition temperature of at least 90° C. and an elastic modulus of at least 100 GPa.

13. The system of claim 12 , wherein the second polymer is characterized by a glass transition temperature and elastic modulus higher than first polymer material.

14. The system of claim 1 , wherein the interrogator system comprises a Raman or Brillouin backscattering detector.

15. The system of claim 1 , wherein the interrogator system comprises wavelength division multiplexing (DWDM) switch.

16. The system of claim 15 , wherein the interrogator system further comprises an optical coupler.

17. The system of claim 1 , wherein the wellbore is an offshore wellbore, the system further comprising a wellhead at the top of the wellbore, wherein the interrogator is positioned adjacent the wellhead of the offshore wellbore.

18. A wellbore leak detection method comprising:
coupling an exterior surface of a distributed acoustic sensing cable disposed in a wellbore to an optical waveguide by directly encasing the optical waveguide in a polymer composite so that the polymer composite is in contact with the optical waveguide,
wherein the polymer composite includes reinforcement fibers embedded throughout the polymer composite; and
wherein the polymer composite enhances a sensitivity of the optical waveguide to a cable elongation effect; and

transmitting through the polymer composite to the optical waveguide a strain applied to the exterior surface of the cable.

19. The method of claim 18 , further comprising propagating a signal source along the optical waveguide; and receiving a return signal source from the location of the applied strain.

20. The method of claim 19 , further comprising combining multiple wavelengths on the optical waveguide.

21. The method of claim 18 , further comprising deploying the distributed acoustic sensing cable in a wellbore on a tubular member.

Assignees

• Halliburton Energy Services Inc

Inventors

• Xia Hua
• Taware Avinash V
• Barfoot David A

Classifications

• G01V1/52

  Structural details · CPC title

• G01V1/46

  Data acquisition · CPC title

• G01V1/40

  specially adapted for well-logging · CPC title

• E21B47/06 Primary

  Measuring temperature or pressure · CPC title

• E21B47/135

  using light waves, e.g. infrared or ultraviolet waves · CPC title