Method and apparatus for downhole photon imaging

Patent metadata

Field	Value
Publication number	US-9759834-B2
Application number	US-201314758695-A
Country	US
Kind code	B2
Filing date	Dec 30, 2013
Priority date	Dec 30, 2013
Publication date	Sep 12, 2017
Grant date	Sep 12, 2017

Abstract

Method and apparatus for downhole photon imaging. The downhole photon imaging apparatus includes a photon source that emits photons; a scintillation device that generates a light signal in response to received photons; a light sensing device coupled with the scintillation device for generating an electronic signal in response to a received light signal; and a collimator coupled with the scintillation device which has a design that allows photons with single Compton backscattering and backscattered at a pre-determined backscattering angle to be detected by the scintillation device.

First claim

What is claimed is:

1. An apparatus for downhole photon imaging, comprising:
a photon source that emits photons;
a pair of scintillation devices that generates a light signal in response to received photons, the pair of scintillation devices disposed symmetrically about the photon source, each scintillation device being positioned so that it only receives backscattered photons emitted from the photon source;
a light sensing device coupled with each scintillation device, the light sensing device generating an electronic signal in response to a received light signal; and
a collimator coupled with each scintillation device, the collimator having a design that allows photons with single Compton backscattering and backscattered at a pre-determined backscattering angle to be detected by the scintillation device.

2. The apparatus of claim 1 , further comprising a housing containing the photon source, the scintillation device, the light sensing device and the collimator.

3. The apparatus of claim 1 , wherein the photon source comprises a chemical source Cs-137, induced gamma-rays from neutron activation or an electronic source.

4. The apparatus of claim 1 , wherein the photon source comprises an x-ray tube.

5. The apparatus of claim 1 , wherein the photon source emits photons at one or more energy levels, or over a range of energy levels.

6. The apparatus of claim 1 , wherein the scintillation device comprises a gamma-ray scintillator or a solid state detector.

7. The apparatus of claim 1 , wherein the light sensing device comprises a photomultiplier or a photodiode.

8. The apparatus of claim 1 , further comprising means to enhance light transmission between the scintillation device and the light sensing device.

9. The apparatus of claim 1 , wherein the distance between the photon source and the scintillation device is less than 12 inches.

10. A method for downhole photon imaging, comprising:
providing a downhole photon imaging apparatus in a borehole casing, the downhole photon imaging apparatus comprising:
a photon source emitting photons;
a pair of scintillation devices that generates a light signal in response to received photons, the pair of scintillation devices disposed symmetrically about the photon source, each scintillation device being positioned so that it only receives backscattered photons emitted from the photon source;
a light sensing device coupled with each scintillation device, the light sensing device generating an electronic signal in response to a received light signal;
a collimator coupled with each scintillation device, the collimator having an design that allows photons with single Compton backscattering and backscattered at a pre-determined backscattering angle to be detected by the scintillation device; and
moving the downhole photon imaging apparatus in the borehole casing to scan a target object of interest.

11. The method of claim 10 , wherein the downhole photon imaging apparatus further comprises a housing containing the photon source, the scintillation device, the light sensing device and the collimator.

12. The method of claim 10 , wherein the photon source comprises a chemical source Cs-137, induced gamma-rays from neutron activation or an electronic source.

13. The method of claim 10 , wherein the photon source comprises an x-ray tube.

14. The method of claim 10 , wherein the photon source emits photons at one or more energy levels, or over a range of energy levels.

15. The method of claim 10 , wherein the scintillation device comprises a gamma-ray scintillator or a solid state detector.

16. The method of claim 10 , wherein the light sensing device comprises a photomultiplier or a photodiode.

17. The method of claim 10 , wherein the downhole photon imaging apparatus further comprises means to enhance light transmission between the scintillation device and the light sensing device.

18. The method of claim 10 , wherein the distance between the photon source and the scintillation device is less than 12 inches.

Assignees

• Halliburton Energy Services Inc

Inventors

• Lee Dongwon
• Guo Weijun

Classifications

• G01V5/125 Primary

  and detecting the secondary gamma- or X-rays in different places along the bore hole · CPC title

• G01N23/203

  Measuring back scattering · CPC title

• E21B47/005

  Monitoring or checking of cementation quality or level · CPC title

• G01V5/08 Primary

  using primary nuclear radiation sources or X-rays {(, e.g. for inducing radioactivity; investigating or analysing materials by the use of wave or particle radiation, e.g. X-rays, neutrons G01N23/00)} · CPC title

• G01T1/2018

  Scintillation-photodiode combinations · CPC title