Spatial heterodyne integrated computational element (SH-ICE) spectrometer

Patent metadata

Field	Value
Publication number	US-9229126-B2
Application number	US-201214428270-A
Country	US
Kind code	B2
Filing date	Sep 13, 2012
Priority date	Sep 13, 2012
Publication date	Jan 5, 2016
Grant date	Jan 5, 2016

Abstract

A spatial heterodyne spectrometer may employ an integrated computational element (ICE) to obtain a measure of one or more fluid properties without requiring any moving parts, making it particularly suitable for use in a downhole environment. One illustrative method embodiment includes: directing light from a light source to illuminate a sample; transforming light from the sample into spatial fringe patterns using a dispersive two-beam interferometer; adjusting a spectral weighting of the spatial fringe patterns using an integrated computation element (ICE); focusing spectral-weight-adjusted spatial fringe patterns into combined fringe intensities; detecting the combined fringe intensities; and deriving at least one property of the sample.

First claim

What is claimed is:

1. A spectral analysis tool that comprises:
a light source that illuminates a sample;
a detector;
an optical path that couples light that has interacted with the sample to the detector;
a dispersive two-beam interferometer that transforms light propagating along the path into spatial fringe patterns associated with corresponding wavelengths; and
an integrated computational element (ICE) that adjusts a spectral weighting of light propagating along the optical path.

2. The tool of claim 1 , wherein the ICE has a programmable wavelength dependent attenuation.

3. The tool of claim 1 , wherein the ICE employs spatially-dependent masking to adjust the spectral weighting based on a spatial dependence of the spatial fringe patterns.

4. The tool of claim 3 , wherein the ICE has a programmable spatial dependence.

5. The tool of claim 3 , wherein the ICE further employs wavelength dependent masking.

6. The tool of claim 5 , wherein the wavelength dependence is programmable.

7. The tool of claim 3 , wherein the ICE is a multiplex device employing multiple different row-oriented spectral weighting regions to provide multiple adjustments to the spectral weighting.

8. The tool of claim 1 , wherein the ICE employs multiple different row-oriented spectral weighting regions to provide multiplex adjustments to the spectral weighting.

9. The tool of claim 1 , further comprising a focusing element that recombines one or more rows of spatial fringe pattern information at row-associated points.

10. The tool of claim 9 , wherein the detector comprises an array of detectors that capture row-associated combined intensity measurements at the row-associated points.

11. The tool of claim 1 , wherein the detector acquires a two-dimensional image of spectral-weight-adjusted spatial fringe patterns, and wherein row-oriented spatial fringe pattern information is combined electronically.

12. The tool in claim 1 , wherein detector acquires a two-dimensional image of spectral-weight-adjusted spatial fringe patterns, and wherein row-oriented spatial fringe pattern information is Fourier transformed electronically.

13. The tool of claim 1 , wherein the spectral analysis tool is integrated into a downhole wireline or logging-while-drilling instrument package.

14. The tool of claim 13 , wherein said sample includes fluid drawn from a formation.

15. The tool of claim 13 , wherein the sample includes a portion of a borehole wall.

16. The tool of claim 13 , wherein the sample includes fluid from a borehole.

17. A spectral analysis method that comprises:
directing light from a light source to illuminate a sample;
transforming light from the sample into spatial fringe patterns using a dispersive two-beam interferometer;
adjusting a spectral weighting of the spatial fringe patterns using an integrated computation element (ICE);
detecting combined fringe intensities derived from spectral-weight-adjusted spatial fringe patterns; and
deriving at least one property of the sample.

18. The method of claim 17 , wherein said detecting includes focusing spectral-weight-adjusted spatial fringe patterns into combined fringe intensities.

19. The method of claim 17 , wherein said operations of directing, transforming, adjusting, focusing, and detecting are performed in a downhole tool.

20. The method of claim 19 , further comprising modifying operation of the downhole tool based on said property.

21. The method of claim 17 , wherein said adjusting includes applying a spatially-dependent mask to the spatial fringe patterns.

22. The method of claim 21 , wherein the spatially-dependent mask further applies a wavelength-dependent attenuation.

23. The method of claim 17 , wherein said adjusting includes applying different masks in multiple row-oriented regions.

24. The method of claim 17 , wherein said detecting includes:
sensing spectral-weight-adjusted spatial fringe patterns with a two-dimensional array of detectors; and
electronically combining measurements along a row dimension to obtain the combined fringe intensities.

25. The method of claim 24 , further comprising further comprising applying a spatial Fourier transform to the sensed spectral-weight-adjusted spatial fringe patterns.

26. The method of claim 17 , wherein the downhole sample is a fluid drawn from a port seated against a borehole wall.

27. The method of claim 17 , wherein the sample is a borehole fluid or a portion of a borehole wall.

28. The method of claim 17 , wherein the property is at least one of: a contamination level, a quantity of at least one fluid type, and a concentration of at least one substance.

Assignees

• Perkins David L
• Halliburton Energy Services Inc

Inventors

• Perkins David L

Classifications

• G01N33/0009

  General constructional details of gas analysers, e.g. portable test equipment (devices for withdrawing samples in the gaseous state G01N1/22) · CPC title

• G01N33/28

  Oils {, i.e. hydrocarbon liquids} (edible oils or edible fats G01N33/03) · CPC title

• G01V8/00 Primary

  Prospecting or detecting by optical means · CPC title

• G01N21/31

  Investigating relative effect of material at wavelengths characteristic of specific elements or molecules, e.g. atomic absorption spectrometry {(G01N21/72 takes precedence)} · CPC title

• E21B49/08

  Obtaining fluid samples or testing fluids, in boreholes or wells · CPC title