DAS FOR WELL RANGING

• US 20170260839A1
• Filed: 03/08/2017
• Published: 09/14/2017
• Est. Priority Date: 03/09/2016
• Status: Abandoned Application

• Current Assignee: Conocophillips Company (ConocoPhillips)
• Original Assignee: Conocophillips Company (ConocoPhillips)
• Inventors: BEARDMORE, David Hale, MOSHER, Charles C., SMITH, Bruce E., ATA, Elias Z., FILICE, Frank P.
• Application Number:
  US15/453,517
• Publication Number:
  US 20170260839A1
• Time in Patent Office: Days
• CPC Class Codes: E21B 43/26 by forming crevices or fractures
• CPC Class Codes: E21B 47/0224 using seismic or acoustic means
• CPC Class Codes: E21B 47/0228 using electromagnetic energy or detectors therefor
• CPC Class Codes: E21B 47/07 Temperature
• CPC Class Codes: E21B 47/101 using acoustic energy
• CPC Class Codes: E21B 47/102 using electrical indications: using light radiations
• CPC Class Codes: E21B 47/107 using acoustic means
• CPC Class Codes: E21B 47/135 using light waves, e.g. infrared or ultraviolet waves
• CPC Class Codes: G01B 11/161 by interferometric means
• CPC Class Codes: G01H 9/004 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 Class Codes: G01K 11/32 using changes in transmittance, scattering or luminescence in optical fibres
• CPC Class Codes: G01V 1/226 Optoseismic systems
• CPC Class Codes: G01V 1/40 specially adapted for well-logging

Abstract

Using distributed acoustic sensing (DAS) fiber optic cable for borehole surveying and/or well ranging.

Claims

1. ) A method of well ranging comprising:

a) providing a first distributed acoustic sensing (DAS) fiber optic cable in a first reference well, said DAS cable operably connected to a Optical Time Domain Reflectometer (OTDR);

b) providing a second distributed acoustic sensing (DAS) fiber optic cable in a second reference well, said DAS cable operably connected to a Optical Time Domain Reflectometer (OTDR);

c) generating a laser light signal in said first and second DAS fiber optic cables;

d) generating an acoustic signal in a test well;

e) receiving a perturbed light signal in said first and second DAS cables;

f) recording said received signal using said OTDR(s);

g) processing said recorded signal using a computer having a signal processing program therein;

h) determining a distance between said test well and said reference well based on said processed signal.

2. ) The method of claim 1, wherein said OTDR is a coherent-OTDR (C-OTDR).

3. ) The method of claim 1, wherein each said first and second DAS cable has a separate OTDR.

4. ) The method of claim 1, wherein said first and second DAS cable share an OTDR.

5. ) The method of claim 1, wherein said test well is within 50 m of said reference well.

6. ) The method of claim 1, wherein said test well is within 10 m of said reference well.

7. ) The method of claim 1, wherein said test well is within 1 m of said reference well.

8. ) The method of claim 1, wherein said test well follows a preplanned drilling pathway and eventually intersects said reference well.

9. ) The method of claim 1, wherein said OTDR is a coherent-OTDR (C-OTDR).

10. ) The method of claim 1, wherein said determining step is performed by a program stored in a computer.

11. ) The method of claim 10, wherein said display is a 3D display and said map is a 3D map.

12. ) The method of claim 1, including the further step of printing, displaying or saving to a non-transitory machine-readable storage medium the recorded or processed signals (or both).

13. ) A paper or plastic printout or a 3D display of the recorded or processed signals of the method of claim 1.

14. ) A 3D display of the map of the method of claim 11.

15. ) A non-transitory machine-readable storage medium containing or having saved thereto the recorded or processed signals (or both) of the method of claim 1.

16. ) A non-transitory machine-readable storage medium, which when executed by at least one processor of a computer, performs the determining step of the method of claim 1.

17. ) The method according to claim 1, wherein an active drill bit provides said acoustic signal.

19. ) The method of claim 10, wherein said OTDR is a coherent-OTDR (C-OTDR).

21. ) The method of claim 12, wherein said C-OTDR is a high coherence C-OTDR.

22. ) The method of claim 12, wherein first and second DAS cables are provided in first and second reference wells, providing two processed signals used for triangulation.

18. ) A method of drilling a preplanned wellbore pathway, comprising:

a) providing a distributed acoustic sensing (DAS) fiber optic cable in a reference well, said DAS cable operably connected to a Optical Time Domain Reflectometer (OTDR);

b) generating a light signal in said DAS cable;

c) generating an acoustic signal in an active well being drilled to follow a preplanned wellbore pathway;

d) receiving a perturbed light signal in said DAS cable;

e) recording said received signal using said OTDR;

f) processing said recorded signal to determine a distance and direction between said test well and said reference well based on said processed signal; and

g) controlling a drilling trajectory of a drill bit in said active well based on said distance and said direction so that said drill bit follows said preplanned wellbore pathway.

20. ) A method of drilling a preplanned wellbore pathway, comprising:

a) providing a distributed acoustic sensing (DAS) fiber optic cable in a reference well, said DAS cable operably connected to a Coherent Optical Time Domain Reflectometer (C-OTDR);

b) generating an intermittent laser light signal in said DAS cable;

c) generating an acoustic signal in an active well being drilled to follow a preplanned wellbore pathway;

d) receiving a backscatter signal in said DAS cable, wherein said laser light signal is perturbed by said acoustic signal to produce said backscatter signal;

e) recording said backscatter signal using said C-OTDR;

f) processing said recorded signal to determine a distance and direction between said active well and said reference well;

g) displaying a map of said active well, said reference well, and said preplanned wellbore pathway;

h) controlling a trajectory of a drill bit in said active well based on said map so that said drill bit and active well follows said preplanned wellbore pathway.