Systems and methods to reduce acoustic noise in fiber optic based sensor systems

Patent metadata

Field	Value
Publication number	US-11268834-B2
Application number	US-201716467834-A
Country	US
Kind code	B2
Filing date	Feb 28, 2017
Priority date	Feb 28, 2017
Publication date	Mar 8, 2022
Grant date	Mar 8, 2022

Abstract

The disclosed embodiments include an acoustic noise reduction device. In one embodiment, the device includes a first sensor operable to detect a first acoustic noise signal and a desired signal and to modulate a first plurality of optical signals in response to detecting at least one of the first acoustic noise signal and the desired signal. The device also includes a second sensor operable to detect a second acoustic noise signal and modulate a second plurality of optical signals in response to detecting the second acoustic noise signal. The device further includes a coupler that is connected to the first and second sensors, where components of the modulated first and second plurality of optical signals approximately cancel each other out.

First claim

We claim:

1. An acoustic noise reduction device comprising:
a first sensor connected to a first segment of optical fiber and operable to:
detect acoustic noise signals and desired signals; and
perform a first modulation of a first plurality of optical signals traversing the first segment of the optical fiber in response to detecting at least one of the acoustic noise signals and the desired signals,
wherein the first modulation creates at least one of a first phase shift to the first plurality of optical signals due to the acoustic noise signals and a second phase shift to the first plurality of optical signals due to the desired signals;

a second sensor coupled to the first sensor and connected to a second segment of the optical fiber, the second sensor operable to:
detect the acoustic noise signals; and
perform a second modulation of a second plurality of optical signals traversing the second segment of the optical fiber in response to detecting the acoustic noise signals,
wherein the second modulation creates a first phase shift to the second plurality of optical signals due to the acoustic noise signals, the first phase shift to the first plurality of optical signals being approximately identical to the first phase shift to the second plurality of optical signals; and

a coupler connected to the first and the second segments of optical fibers, and connected to a third segment of the optical fiber, the coupler operable to:
receive the first and second pluralities of modulated optical signals,
wherein the first phase shift to the first plurality of optical signals approximately cancels out the first phase shift to the second plurality of optical signals due to the first phase shift of the first plurality of optical signals and the first phase shift of the second plurality of optical signals being approximately identical.

2. The acoustic noise reduction device of claim 1 , wherein the first and second sensors comprise a piezoelectric material operable to convert an electrical signal into a mechanical strain to adjust a first distance from the first sensor to the coupler and a second distance from the second sensor to the coupler, respectively.

3. The acoustic noise reduction device of claim 1 , further comprising:
a first reflector operable to direct the first plurality of modulated optical signals to traverse the first segment of the optical fiber towards the coupler; and
a second reflector operable to direct the second plurality of modulated optical signals to traverse the second segment of the optical fiber.

4. The acoustic noise reduction device of claim 1 , wherein the coupler is further operable to pass the first and second pluralities of modulated signals to a square-law detector operable to detect the desired signals from the first and second pluralities of modulated signals.

5. The acoustic noise reduction device of claim 1 , wherein the coupler is further operable to pass the first and second pluralities of modulated signals to an optical detector operable to detect the desired signals from the first and second pluralities of modulated signals.

6. The acoustic noise reduction device of claim 1 , wherein the coupler is further operable to:
receive a third plurality of optical signals from the third segment of the optical fiber;
divert a first component of the third plurality optical signals to the first segment of the optical fiber; and
divert a second component of the third plurality optical signals to the second segment of the optical fiber,
wherein the first component of the third plurality optical signals provides power to the first sensor, and
wherein the second component of the third plurality optical signals provides power to the second sensor.

7. The acoustic noise reduction device of claim 6 , wherein the first component of the third plurality optical signals and the second component of the third plurality optical signals have approximately identical signal intensities.

8. The acoustic noise reduction device of claim 1 , wherein the acoustic noise reduction device is deployed along a casing deployed in a wellbore of a hydrocarbon production environment.

9. An acoustic noise reduction system, comprising:
a first primary coupler;
a second primary coupler connected to the first primary coupler via a first primary segment of optical fiber;
a first acoustic noise reduction device being connected to the first primary coupler via a second primary segment of the optical fiber; and
a second acoustic noise reduction device being connected to the second primary coupler via a third primary segment of the optical fiber, wherein each of the first and second acoustic noise reduction devices comprises:
a first sensor connected to a first secondary segment of the optical fiber and operable to:
detect acoustic noise signals and desired signals; and
perform a first modulation of a first plurality of optical signals traversing the first secondary segment of the optical fiber in response to detecting at least one of the acoustic noise signals and the desired signals,
wherein the first modulation creates at least one of a first phase shift to the first plurality of optical signals due to the acoustic noise signals and a second phase shift to the first plurality of optical signals due to the desired signals;

a second sensor coupled to the first sensor and connected to a second secondary segment of the optical fiber, the second sensor operable to:
detect the acoustic noise signals; and
perform a second modulation of a second plurality of optical signals traversing the second secondary segment of the optical fiber in response to detecting the acoustic noise signals,
wherein the second modulation creates a first phase shift to the second plurality of optical signals due to the acoustic noise signals, the first phase shift to the first plurality of optical signals being approximately identical to the first phase shift to the second plurality of optical signals; and

a secondary coupler connected to the first and the second secondary segments of optical fibers, and connected to a third segment of the optical fiber, the coupler operable to:
receive the first and second pluralities of modulated optical signals,
wherein the first phase shift to the first plurality of optical signals approximately cancels out the first phase shift to the second plurality of optical signals due to the first phase shift of the first plurality of optical signals and the first phase shift of the second plurality of optical signals being approximately identical.

10. The acoustic noise reduction system of claim 9 , wherein the first sensor of the first acoustic noise reduction device is operable to detect a first desired signals, wherein the first sensor of the second acoustic noise reduction device is operable to detect a second desired signals, and wherein the first desired signals and the second desired signals have different signals characteristics.

11. The acoustic noise reduction system of claim 10 , wherein the first desired signals and the second desired signals are indicative of different types of wellbore conditions.

12. The acoustic noise reduction system of claim 11 , wherein the different types of wellbore conditions comprise pressure, temperature, pH, and humidity at a wellbore location proximate to one of the first and second acoustic noise reduction devices.

13. The acoustic noise reduction system of claim 10 , further comprising a multiplexer configured to:
multiplex optical signals indicative of the first desired signals with optical signals indicative of the second desired signals to form a multiplexed signals; and
transmit the

Assignees

• Halliburton Energy Services Inc

Inventors

• Capoglu Ilker R
• Lan Xinwei
• Martinez Yenny Natali
• Maida John L

Classifications

• G01V8/24

  using optical fibres · CPC title

• G01L1/242 Primary

  the material being an optical fibre · CPC title

• G01H9/004

  using fibre optic sensors (light guides per se G02B6/00, acousto-optical devices specially adapted for gating or modulating in optical wave guides G02F1/125) · CPC title

• G01D5/353 Primary

  influencing the transmission properties of an optical fibre · CPC title

• G01K11/32

  using changes in transmittance, scattering or luminescence in optical fibres · CPC title