Measurement system with disposable fiber with strain coupling in lateral wells

Patent metadata

Field	Value
Publication number	US-11549369-B1
Application number	US-202117643755-A
Country	US
Kind code	B1
Filing date	Dec 10, 2021
Priority date	Dec 10, 2021
Publication date	Jan 10, 2023
Grant date	Jan 10, 2023

Abstract

A wellbore optical fiber measurement system for measuring data in a lateral wellbore that includes a flexible optical fiber. The optical fiber includes a waveguide coated with a coating, wherein the optical fiber has an effective density ρ eff fiber and an effective axial Young modulus E eff fiber and wherein the product
( ρ eff f ⁢ i ⁢ b ⁢ e ⁢ r E eff f ⁢ i ⁢ b ⁢ e ⁢ r ) · ( 1 - ρ w ⁢ a ⁢ t ⁢ e ⁢ r ρ eff f ⁢ i ⁢ b ⁢ e ⁢ r )
is greater than 50 kg/m3/GPa. The system also includes a data acquisition unit with a processor operable to obtain strain measurement data of the wellbore from the optical fiber.

First claim

What is claimed is:

1. A wellbore optical fiber measurement system for measuring data in a lateral wellbore, comprising:
a flexible optical fiber comprising a waveguide coated with a coating, wherein the optical fiber has an effective density ρ eff fiber and an effective axial Young modulus E eff fiber and wherein a strain coupling parameter comprises the product

(

ρ

eff
fiber

E

eff
fiber

)

·

(

1
-

ρ

w
⁢
a
⁢
t
⁢
e
⁢
r

ρ

eff
fiber

)

and is greater than 100 kg/m 3 /GPa under downhole conditions; and
a data acquisition unit comprising a processor operable to obtain strain measurement data of the wellbore from the optical fiber.

2. The system of claim 1 , wherein the optical fiber comprises an acrylate-coated optical fiber overcoated with a material comprising a polymer wherein a density of the material is greater than 1000 kg/m 3 .

3. The system of claim 1 , wherein the optical fiber comprises an acrylate-coated optical fiber overcoated with a material comprising a polymer and a filler wherein a density of the material is greater than 1000 kg/m 3 .

4. The system of claim 3 , wherein the material comprises a volume fraction selected to maximize the value of

(

ρ
E

)

of the material.

5. The system of claim 3 , wherein the material comprises a volume fraction selected to maximize the strain coupling parameter of the optical fiber for an outer diameter of the optical fiber.

6. The system of claim 3 , wherein the wellbore includes a wellbore fluid having a wellbore fluid density ρ fluid and wherein the polymer material comprises a volume fraction selected to maximize the strain coupling parameter of the optical fiber for an outer diameter of the optical fiber and the wellbore fluid density ρ fluid .

7. The system of claim 1 , wherein a roughness of an outer surface of the optical fiber is manipulated to increase a friction coefficient of the optical fiber.

8. A method of measuring strain in a lateral wellbore in a subterranean formation, the method comprising:
disposably installing a flexible optical fiber, comprising a waveguide coated with a coating, in the wellbore so as to be strain coupled with a wall of the wellbore; and
interrogating the optical fiber with a data acquisition unit to measure strain experienced by the wellbore wall;
wherein the optical fiber has an effective density ρ eff fiber and an effective axial Young modulus E eff fiber ; and
wherein a strain coupling parameter comprises the product

(

ρ

eff
fiber

E

eff
fiber

)

·

(

1
-

ρ

w
⁢
a
⁢
t
⁢
e
⁢
r

ρ

eff
fiber

)

and is greater than 100 kg/m 3 /GPa under downhole conditions.

9. The method of claim 8 , wherein the optical fiber comprises an acrylate-coated optical fiber overcoated with a material comprising a polymer wherein a density of the material greater than 1000 kg/m 3 .

10. The method of claim 8 , wherein the optical fiber comprises an acrylate-coated optical fiber overcoated with a material comprising a polymer and a filler wherein a density of the material is greater than 1000 kg/m 3 .

11. The method of claim 10 , wherein the material comprises a volume fraction selected to maximize the value of

(

ρ
E

)

of the material.

12. The method of claim 10 , wherein the polymer material comprises a volume fraction selected to maximize the strain coupling parameter of the optical fiber for an outer diameter of the optical fiber.

13. The method of claim 10 , wherein the wellbore includes a wellbore fluid having a wellbore fluid density ρ fluid and wherein the material comprises a volume fraction selected to maximize the strain coupling parameter of the optical fiber for an outer diameter of the optical fiber and the wellbore fluid density ρ fluid .

14. The method of claim 8 , wherein a roughness of an outer surface of the optical fiber is manipulated to increase a friction coefficient of the optical fiber.

15. A system for fracturing a first lateral wellbore in a subterranean formation with a second lateral wellbore proximate the first wellbore, comprising:
wellbore fracturing equipment comprising one or more frac pumps operable to frac the first lateral wellbore;
a flexible optical fiber located in the second lateral wellbore and comprising a waveguide coated with a coating, wherein the optical fiber has an effective density ρ eff fiber and an effective axial Young modulus E eff fiber and wherein a strain coupling parameter comprises the product

(

ρ

eff
fiber

E

eff
fiber

Assignees

• Halliburton Energy Services Inc

Inventors

• Leblanc Michel
• Jaaskelainen Mikko K

Classifications

• E21B49/006 Primary

  Measuring wall stresses in the borehole · CPC title

• G01L1/242 Primary

  the material being an optical fibre · CPC title

• E21B43/2607

  Surface equipment specially adapted for fracturing operations · CPC title

• G02B6/02395

  Glass optical fibre with a protective coating, e.g. two layer polymer coating deposited directly on a silica cladding surface during fibre manufacture (G02B6/02052, G02B6/02057, G02B6/024, G02B6/032, G02B6/105, G02B6/14 take precedence; coating on fibre gratings G02B6/02104; multilayer core or cladding G02B6/036; reinforcing splice joints G02B6/2558; optical cables, i.e. comprising protective structures external to the protective coating such as a jacket or plural coated optical fibres G02B6/44; coating of glass to obtain optical fibres C03C25/104) · CPC title

• G01V1/52

  Structural details · CPC title