Distributed Temperature Sensing System with Remote Reference Coil

• US 20060115204A1
• Filed: 11/17/2005
• Published: 06/01/2006
• Est. Priority Date: 05/23/2003
• Status: Abandoned Application

• Current Assignee: Schlumberger Technology Corporation (SLB)
• Original Assignee: Schlumberger Technology Corporation (SLB)
• Inventors: Marsh, Richard, Hartog, Arthur H., Vaynshteyn, Vladimir, Naldrett, Garth
• Application Number:
  US11/164,291
• Publication Number:
  US 20060115204A1
• Time in Patent Office: Days
• US Class Current: 385/12
• CPC Class Codes: E21B 47/07 Temperature
• CPC Class Codes: G01K 11/32 using changes in transmittance, scattering or luminescence in optical fibres
• CPC Class Codes: G01K 11/3206 at discrete locations in the fibre, e.g. using Bragg scattering

Abstract

The invention is an optical fiber distributed temperature sensing system comprising an opto-electronic unit and a sensing optical fiber, which system measures temperature so as to provide a temperature profile along at least part of the length of the optical fiber. The system includes reference coils, which are temperature reference points, at a location that is remote from the opto-electronic unit and closer to the region whose temperature is being measured.

Claims

1. An optical fiber distributed temperature sensing system, comprising:

an opto-electronic unit and an optical fiber functionally connected to the opto-electronic unit;

the opto-electronic unit adapted to transmit optical energy into the optical fiber and to receive backscattered signals reflected from the optical fiber in order to measure temperature;

the optical fiber including at least one reference coil at a known temperature; and

the reference coil located remote from the opto-electronic unit.

2. The system of claim 1, wherein the optical fiber is deployed in a subterranean wellbore.

3. The system of claim 2, wherein the at least one reference coil is located in the wellbore.

4. The system of claim 2, wherein the wellbore is a subsea wellbore.

5. The system of claim 1, wherein the temperature at the reference coil is measured by a separate sensor.

6. The system of claim 1, wherein the temperature at the reference coil is measured by a separate optical fiber functionally connected to the opto-electronic unit.

7. The system of claim 1, wherein the temperature at the reference coil is measured by the optical fiber with an optical pulse having unique characteristics.

8. The system of claim 1, wherein the temperature at the reference coil is measured by use of a thermal model.

9. The system of claim 1, wherein the optical fiber is deployed along a pipeline.

10. The system of claim 9, wherein the pipeline is a subsea pipeline.

11. The system of claim 1, wherein the optical fiber is deployed on a structure.

12. The system of claim 11, wherein the structure is a process vessel.