Acoustic sensor apparatus, systems, and methods

Patent metadata

Field	Value
Publication number	US-9562985-B2
Application number	US-201114241039-A
Country	US
Kind code	B2
Filing date	Sep 26, 2011
Priority date	Sep 26, 2011
Publication date	Feb 7, 2017
Grant date	Feb 7, 2017

Abstract

In some embodiments, an apparatus and a system, as well as a method and an article, may operate to acquire multiple output values provided by at least one elongated, unitary acoustic sensor operating as a secondary propagation medium. The sensor has multiple mechanical-to-electrical conversion probe points along its length, to provide corresponding multiple output values proportional to mechanical movement along the length of the sensor, the mechanical movement being induced by acoustic waves in a primary propagation medium comprising a geological formation and borehole fluid. Further activity may include processing the output values to determine slowness in an acoustic wave propagating between at least two of the probe points. Additional apparatus, systems, and methods are disclosed.

First claim

What is claimed is:

1. A processor-implemented method, comprising:
acquiring multiple output values from mechanical-to-electrical conversion provided by at least one elongated, unitary acoustic sensor operating as a secondary propagation medium with multiple probe points along a length of the at least one elongated, unitary acoustic sensor to provide the multiple output values proportional to mechanical movement along the length of the at least one elongated, unitary acoustic sensor, the output values being electrical values of voltage or current from the at least one elongated, unitary acoustic sensor at respective locations along the length of the at least one elongated, unitary acoustic sensor, the mechanical movement being induced by acoustic waves in a primary propagation medium comprising a geological formation and borehole fluid, an elongated, unitary acoustic sensor being an undivided sensor of single, continuous material, the undivided sensor capable of carrying an received acoustic wave along its length in an uninterrupted fashion such that mechanical movement of the undivided sensor along the length of the undivided sensor occurs in response to the received acoustic wave being carried across the length of the undivided sensor; and
processing the output values to determine slowness in an acoustic wave propagating between at least two of the probe points.

2. The method of claim 1 , wherein the processing further comprises:
inverting the output values to provide a decoupled sampled signal.

3. The method of claim 2 , further comprising:
transforming the decoupled sampled signal to provide a normalized version of the decoupled sampled signal having normalized amplitudes.

4. The method of claim 2 , further comprising:
transforming the decoupled sampled signal, or a normalized version of the decoupled sampled signal to determine a time shift between the output values.

5. The method of claim 4 , wherein determining the time shift comprises interpolating arrival times between the output values.

6. The method of claim 4 , wherein determining the time shift comprises one of calculating an average time shift or ignoring the time shift for maximal or minimal magnitude values of the normalized amplitudes.

7. The method of claim 4 , wherein determining the time shift comprises, for an output value corresponding to one of the probe points, locating a point in time for an adjacent probe output value that has an amplitude approximately equal to an amplitude associated with the output value corresponding to the one of the probe points.

8. The method of claim 4 , wherein determining the slowness comprises:
dividing the time shift by a distance along the length of the at least one elongated, unitary sensor between corresponding ones of the probe points.

9. The method of claim 1 , further comprising:
determining a radial velocity of the geological formation, based on the slowness.

10. The method of claim 1 , further comprising:
reducing noise in the slowness by averaging velocity information over a layer of the geological formation to reduce noise in the slowness.

11. The method of claim 1 , further comprising:
comparing velocity values in the slowness, along the length of the at least one elongated, unitary sensor, to determine a layer boundary in the geological formation.

12. The method of claim 1 , wherein the acquiring comprises:
acquiring the multiple output values from the at least one elongated, unitary sensor comprising a hollow cylinder.

13. The method of claim 1 , wherein the acquiring comprises:
acquiring the multiple output values from the at least one elongated, unitary acoustic sensor comprising at least one pair of substantially opposing elongate solids.

14. An apparatus, comprising:
at least one elongated, unitary acoustic sensor to operate as a secondary propagation medium with multiple probe points along a length of the at least one elongated, unitary acoustic sensor to provide corresponding multiple output values from mechanical-to-electrical conversion proportional to mechanical movement along the length of the at least one elongated, unitary acoustic sensor, when the mechanical movement is induced by acoustic waves in a primary propagation medium, the output values being electrical values of voltage or current from the at least one elongated, unitary acoustic sensor at respective locations along the length of the at least one elongated, unitary acoustic sensor, wherein an elongated, unitary acoustic sensor is an undivided sensor of single, continuous material, the undivided sensor capable of carrying an received acoustic wave along its length in an uninterrupted fashion such that mechanical movement of the undivided sensor along the length of the undivided sensor occurs in response to the received acoustic wave being carried across the length of the undivided sensor; and
a processor configured to determine slowness in an acoustic wave propagating between at least two of the probe points, based at least in part on the output values.

15. The apparatus of claim 14 , wherein the at least one elongated, unitary sensor comprises a cylinder.

16. The apparatus of claim 14 , wherein the at least one elongated, unitary sensor comprises a piezoelectric material or piezoelectric material and rubber combination.

17. The apparatus of claim 14 , wherein the at least one elongated, unitary sensor comprises at least one pair of substantially opposing solids, and wherein each one of the pair comprises a separate set of the probe points.

18. A system, comprising:
a housing; and
an apparatus attached to the housing, the apparatus comprising at least one elongated, unitary acoustic sensor to operate as a secondary propagation medium with multiple probe points along a length of the at least one elongated, unitary acoustic sensor to provide corresponding multiple output values from mechanical-to-electrical conversion proportional to mechanical movement along the length of the at least one elongated, unitary acoustic sensor when the mechanical movement is induced by acoustic waves in a primary propagation medium, the output values being electrical values of voltage or current from the at least one elongated, unitary acoustic sensor at respective locations along the length of the at least one elongated, unitary acoustic sensor, an elongated, unitary acoustic sensor being an undivided sensor of single, continuous material, the undivided sensor capable of carrying an received acoustic wave along its length of the undivided sensor occurs in response to the received acoustic wave being carried across the length of the undivided sensor, and a processor configured to determine slowness in an acoustic wave between at least two of the probe points, based at least in part on the output values.

19. The system of claim 18 , wherein the housing comprises:
one of a wireline tool body, a measurement while drilling down hole tool, or a logging while drilling down hole tool.

20. The system of claim 18 , wherein the probe points comprise electrical contacts coupled to inner and outer surfaces of a hollow cylinder.

Assignees

• Donderici Burkay
• Guner Baris
• Halliburton Energy Services Inc

Inventors

• Donderici Burkay
• Guner Baris

Classifications

• G01V1/46 Primary

  Data acquisition · CPC title

• G01V1/44 Primary

  using generators and receivers in the same well (G01V1/52 takes precedence) · CPC title