Transducer configurations and methods for transducer positioning in electrical impedance tomography

• US 8,963,562 B2
• Filed: 08/31/2011
• Issued: 02/24/2015
• Est. Priority Date: 08/31/2011
• Status: Active Grant

• Current Assignee: Baker Hughes, a GE Company, LLC (Baker Hughes Company)
• Original Assignee: General Electric Company
• Inventors: Basu, Wrichik, Meethal, Manoj Kumar Koyithitta, Mahalingam, Sakethraman, Langoju, Rajesh Veera Venkata Lakshmi, Ghoshal, Parama
• Primary Examiner(s): Koval, Melissa
• Assistant Examiner(s): MILLER, DANIEL R
• Application Number:
  US13/222,825
• Publication Number:
  US 20130049770A1
• Time in Patent Office: 1,273 Days
• Field of Search: 738/610.8, 324439-450, 324/600, 324/603, 324/605, 324/609, 324/629, 702/45, 702/47, 702/52, 702/53, 600/393, 600/547, 378/21
• US Class Current: 324/654
• CPC Class Codes: G01N 27/026 Dielectric impedance spectroscopy electrochemical impedance spectroscopy for measuring corrosion G01N17/02
• CPC Class Codes: G01N 33/2823 raw oil, drilling fluid or polyphasic mixtures hydrocarbon content of earth materials G01N33/241; prospecting G01V; drilling per se E21B

Abstract

Transducer configurations and methods for transducer positioning in electrical impedance tomography are provided. A plurality of transducers for one electrical impedance tomography arrangement are configured for positioning proximate a surface of an object and spaced apart along the object, wherein the transducers are one or more conductive rings and have at least one non-conductive portion. The arrangement further includes one or more excitation drivers coupled to the plurality of transducers and configured to generate excitation signals for the plurality of transducers. The arrangement also includes one or more response detectors coupled to the plurality of transducers and configured to measure a response of the object at the plurality of transducers to the excitation applied by the plurality of transducers based on the excitation signals. The arrangement additionally includes a soft-field reconstruction module configured to reconstruct a property distribution based on the excitation signals and the measured response.

Claims

1. A soft-field tomography system comprising:

a plurality of transducers configured for positioning proximate a surface of an object and spaced apart along the object, at least one of the transducers being formed from at least one conductive ring that extends around the object, the at least one conductive ring including a discontinuity that defines a non-conductive portion, wherein the at least one conductive ring includes a continuous portion that extends around at least one-half of a circumference of the object;

one or more excitation drivers coupled to the plurality of transducers and configured to generate excitation signals for the plurality of transducers;

one or more response detectors coupled to the plurality of transducers and configured to measure a response of the object at the plurality of transducers to the excitation applied by the plurality of transducers based on the excitation signals; and

a soft-field reconstruction module configured to reconstruct a property distribution based on the excitation signals and the measured response.

2. The soft-field tomography system of claim 1, wherein the discontinuity in the at least one conductive ring defining the non-conductive portion is positioned at a bottom of the rings within a fluid flow path.

3. The soft-field tomography system of claim 1, wherein the discontinuity in the at least one conductive ring defining the non-conducive portion comprises a non-conductive material.

4. The soft-field tomography system of claim 1 wherein the discontinuity in the at least one conductive ring defining the non-conductive portion comprises a gap.

5. The soft-field tomography system of claim 1, wherein the at least one conductive ring further comprises at least two discontinuities that define a major conductive arc and a minor conductive arc in the conductive rings, wherein the major and minor conductive arcs extend around the object.

6. The soft-field tomography system of claim 5, wherein the minor arc and the non-conductive portions encompass shout two degrees of the conductive rings.

7. The soft-field tomography system of claim 1, wherein the object is a pipe in a non-vertical orientation and having fluid flowing therethrough, the at least one conductive ring positioned within the pipe with the non-conductive portion positioned within the flowing fluid such that the non-conductive portion is in continuous contact with the fluid.

8. The soft-field tomography system of claim 1, wherein the one or more excitation drivers are configured to apply the excitation signals during an excitation sequence, wherein the excitation sequence is based on an application that is optimized using at least one of a signal-to-noise ratio, a resolution, a detection capability, an instrumentation complexity or an acquisition speed.

9. The soft-field tomography system of claim 1, wherein the property distribution is a distribution as determined in one or more of Electrical Impedance Spectroscopy (EIS), Electrical Impedance Tomography (EIT);

Electrical Resistance Tomography (ERT) or Electrical Capacitance Tomography (ECT).

10. The soft-field tomography system of claim 1, wherein the property distribution comprises a distribution of one or more of electrical conductivity or electrical permittivity.

11. A soft-field tomography system comprising:

a plurality of transducers configured for positioning proximate a surface of an object and spaced apart around the object;

at least a subset of the transducers asymmetrically distributed relative to at least another subset of the transducers, wherein the asymmetric transducers in the subsets of transducers;

one or more excitation drivers coupled to the plurality of transducers and configured to generate excitation signals for the plurality of transducers;

one or more response detectors coupled to the plurality of transducers and configured to measure a response of the object at the plurality of transducers to the excitation applied by the plurality of transducers based on the excitation signals; and

a soft-field reconstruction module configured to reconstruct a property distribution based on the excitation signals and the measured response.

12. The soft-field tomography system of claim 11, wherein the transducers form two measurement rings spaced apart along the object, where each of the rings extends around the object.

13. The soft-field tomography system of claim 11, wherein the plurality of transducers comprise at least one of elliptical shaped electrodes, diamond shaped electrodes or triangular shaped electrodes.

14. The soft-field tomography system of claim 13, wherein the electrodes are arranged in different orientations or directions.

15. The soft-field tomography system of claim 11, wherein the object is a pipe in a non-vertical orientation and having fluid flowing therethrough, at least some of the subset of transducers positioned within the flowing fluid to be in continuous contact with the fluid, the subset of transducers having a greater density of distribution than the other subset of transducers.

16. The soft-field tomography system of claim 11, wherein the one or more excitation drivers are configured to generate excitations having at least one of a different phase or amplitude and apply the varying phase or amplitude excitations to the subsets of transducers, wherein a variance of the phase or amplitude between excitations applied to the transducers in the subset of transducers is different than a variance of the phase or amplitude between excitations applied to the transducers in the other subset of transducers.

17. The soft-field tomography system of claim 11, wherein the one or more excitation drivers are configured to apply the excitation signals during an excitation sequence, wherein the excitation sequence is based on an application that is optimized using at least one of a transducer distribution, a signal-to-noise ratio, a resolution, a detection capability, an instrumentation complexity or an acquisition speed.

18. The soft-field tomography system of claim 11, wherein the property distribution is a distribution as determined in one or more of Electrical Impedance Spectroscopy (EIS), Electrical Impedance Tomography (EIT), Electrical Resistance Tomography (ERT) or Electrical Capacitance Tomography (ECT).

19. The soft field tomography system of claim 11, wherein the property distribution comprises a distribution of one or more of electrical conductivity or electrical permittivity.

20. A soft-field tomography system comprising:

a transducer configuration for positioning proximate a surface of an object and spaced along a circumference of the object, the transducer configuration including a conductive strip including a plurality of measurement regions defined by electrodes, at least one of the electrodes surrounded by a non-conductive ring portion, the conductive strip formed from an electrically conductive material and wherein the non-conductive ring portion is surrounded by the electrically conductive material of the conductive strip;

one or more excitation drivers coupled to the electrodes and configured to generate excitation signals for the electrodes;

one or more response detectors coupled to the electrodes and configured to measure a response of the object at the electrodes to the excitation applied by the electrodes based on the excitation signals; and

a soft-field reconstruction module configured to reconstruct a property distribution based on the excitation signals and the measured response.

21. The soft-field tomography system of claim 20, wherein the object is a pipe and the conductive strip defines a ring configured to extend around an inner circumference of the pipe and the electrodes are asymmetrically distributed along the conductive strip.

22. The soft-field tomography system of claim 20, wherein the object is a pipe M anon-vertical orientation and having fluid flowing therethrough, at least some of a subset of electrodes positioned within the flowing fluid to be in continuous contact with the fluid, the subset of transducers having a greater density of distribution than another subset of transducers.