High resolution downhole imaging using signal conversion

• US 9,766,363 B2
• Filed: 07/30/2010
• Issued: 09/19/2017
• Est. Priority Date: 07/30/2010
• Status: Active Grant

• Current Assignee: Halliburton Energy Services Incorporated (Halliburton Company)
• Original Assignee: Halliburton Energy Services Incorporated (Halliburton Company)
• Inventors: Morys, Marian
• Primary Examiner(s): PATIDAR, JAY M
• Application Number:
  US13/811,519
• Publication Number:
  US 20130169279A1
• Time in Patent Office: 2,608 Days
• CPC Class Codes: G01V 11/007 using the seismo-electric effect
• CPC Class Codes: G01V 2210/6163 Electromagnetic
• CPC Class Codes: G01V 3/30 operating with electromagnetic waves

Abstract

Apparatus having a focused transducer and methods of operating a focused transducer downhole in a well can provide high resolution downhole imaging. In various embodiments, a focused transducer is used for imaging downhole in a well in which the imaging is based on a seismoelectric effect. In various embodiments, a focused transducer is used for imaging downhole in a well in which the imaging is based on an electroacoustic effect. Additional apparatus, systems, and methods are disclosed.

Claims

1. An apparatus comprising:

a source to expose a formation to a probe signal;

a sensor to sense a converted signal, the converted signal based on conversion of the probe signal between acoustic energy and electromagnetic energy in the formation, wherein the source or the sensor includes a focused transducer that creates a focused point of high resolution; and

an imaging unit to image the formation using the converted signal.

2. The apparatus of claim 1, wherein the focused transducer includes a focused acoustic transducer.

3. The apparatus of claim 1, wherein the source includes a focused acoustic transducer and the sensor includes a magnetic field sensor.

4. The apparatus of claim 1, wherein the source includes a focused acoustic transducer and the sensor includes electrical electrodes.

5. The apparatus of claim 1, wherein the source includes a magnetic field source and the sensor includes a focused acoustic transducer.

6. The apparatus of claim 1, wherein the source includes electrical electrodes and the sensor includes a focused acoustic transducer.

7. The apparatus of claim 1, wherein the apparatus includes electronics to excite the source.

8. The apparatus of claim 1, wherein the apparatus includes a signal processing unit coupled to the sensor.

9. The apparatus of claim 1, wherein the apparatus includes a communications unit operable to transmit information to earth surface from downhole in a well, the information corresponding to the converted signal.

10. The apparatus of claim 1, wherein the apparatus includes a source of magnetic particles, the source operable to inject the magnetic particles in fluid in pores of the formation.

11. The apparatus of claim 10, wherein the source of magnetic particles includes a source of magnetic nanoparticles.

12. The apparatus of claim 1, wherein a distance between the focus point and the focused transducer is changed downhole.

13. A method comprising:

exposing a formation to a probe signal;

sensing a converted signal, the converted signal based on conversion of the probe signal between acoustic energy and electromagnetic energy in the formation, wherein a focused transducer is used in exposing the formation to the probe signal or in sensing the converted signal, the focused transducer creating a high resolution at a focus point; and

imaging the formation using the converted signal.

14. The method of claim 13, wherein the probe signal is an acoustic signal and the converted signal is an electromagnetic signal.

15. The method of claim 13, wherein exposing the formation to the probe signal includes exposing a formation to a focused acoustic pressure pulse or a focused acoustic continuous wave.

16. The method of claim 13, wherein the probe signal is an electromagnetic signal and the converted signal is an acoustic signal.

17. The method of claim 13, wherein exposing the formation to the probe signal includes exposing the formation to an electromagnetic pulse or an electromagnetic continuous wave;

and

sensing the converted signal includes using a focused acoustic transducer.

18. The method of claim 13, wherein the method includes doping fluid in pores of the formation with magnetic particles.

19. The method of claim 18, wherein doping fluid in pores of the formation with magnetic particles includes doping fluid in pores of the formation with magnetic nanoparticles.

20. The method of claim 19, wherein doping with magnetic nanoparticles includes doping with nanoparticles of iron-containing compositions, vanadium-containing compositions, or both iron-containing compositions and vanadium-containing compositions.

21. The method of claim 13, wherein the method includes:

gating the converted signal to select a signal generated at the apex of a pressure wave; and

filtering with a narrow band matched filter to discriminate the selected signal from noise.

22. The method of claim 13, further comprising varying a distance between the focus point and the focused transducer, with the distance being varied downhole.

23. A non-transitory machine-readable storage medium that stores instructions, which when performed by a machine, cause the machine to perform operations, the operations comprising:

exposing a formation to a probe signal;

controlling sensing of a converted signal, the converted signal based on conversion of the probe signal between acoustic energy and electromagnetic energy in the formation, wherein a focused transducer is used in exposing the formation to the probe signal or in sensing the converted signal, wherein the focused transducer creates a high resolution at a focus point; and

imaging the formation using the converted signal.

24. The non-transitory machine-readable storage medium of claim 23, wherein the operations further include applying a static magnetic field to polarize the formation.

25. The non-transitory machine-readable storage medium of claim 23, wherein the operations further include transmitting information to earth surface from downhole in a well, the information corresponding to the converted signal.

26. The non-transitory machine-readable storage medium of claim 23, wherein the non-transitory machine-readable storage medium includes a non-transitory storage medium distributed among components at a well drilling site.