Apparatuses for generating acoustic waves

• US 20070045038A1
• Filed: 08/26/2005
• Published: 03/01/2007
• Est. Priority Date: 08/26/2005
• Status: Active Grant

• Current Assignee: Halliburton Energy Services Incorporated (Halliburton Company)
• Original Assignee: Halliburton Energy Services Incorporated (Halliburton Company)
• Inventors: Ritter, Thomas, Han, Wei, Birchak, Robert, Kusmer, Dan, Yoo, Kwang, Trainor, William, Van Batenberg, Diederik
• Granted Patent: US 7,591,343 B2
• Time in Patent Office: Days
• US Class Current: 181/113
• CPC Class Codes: G01V 1/02 Generating seismic energy G01V1/003 takes precedence
• CPC Class Codes: G01V 1/40 specially adapted for well-logging

Abstract

An example apparatus for generating acoustic waves is disclosed. The example apparatus includes a housing, and at least one plate having a moment arm, wherein each plate couples to the housing. The example apparatus for generating acoustic also includes at least one axial driver coupled to each moment arm, wherein each axial driver aligns with a longitudinal axis of the housing.

Claims

1. An apparatus for generating acoustic waves, comprising:

a housing;

at least one plate having a moment arm, wherein each plate couples to the housing; and

at least one axial driver coupled to each moment arm, wherein each axial driver aligns with a longitudinal axis of the housing.

2. The apparatus of claim 1 wherein each plate comprises at least one of the following:

a flat portion, a convex portion, or a concave portion.

3. The apparatus of claim 1 further comprising a backing mass coupled to the at least one axial driver, wherein each backing mass is formed of a material selected to compensate for thermal expansion of the housing.

4. The apparatus of claim 1 wherein each plate has a geometric configuration selected to allow the plate to generate acoustic wave beams of varying focal spot size when a signal frequency used to drive the at least one axial driver varies.

5. The apparatus of claim 1 wherein each plate has a geometric configuration and is formed of a material selected to allow the plate to resonate at desired frequencies.

6. The apparatus of claim 1 wherein each plate comprises at least one channel to optimize stiffness of the plate.

7. The apparatus of claim 6 wherein each channel is designed to reduce acoustic waves generated in unwanted modes.

8. The apparatus of claim 1 wherein the at least one plate couples to the at least one axial driver through at least one coupler.

9. The apparatus of claim 8 wherein each coupler is a tapered force shaft having a narrow end at a junction between the tapered force shaft and the at least one plate and a wide end at a junction between the tapered force shaft and the at least one axial driver.

10. The apparatus of claim 1 wherein each axial driver comprises at least one of the following:

a piezoelectric element or a magnetostrictive device.

11. The apparatus of claim 1 further including at least one feedback device coupled to the housing.

12. The apparatus of claim 1 wherein the housing is formed of a fatigue-resistant material.

13. The apparatus of claim 12 wherein the housing is formed of a titanium alloy.

14. An apparatus for generating acoustic waves, comprising:

a housing;

a plate having a moment arm, wherein the plate couples to the housing; and

a pair of axial drivers coupled to the moment arm, wherein the pair of axial drivers aligns with a longitudinal axis of the housing.

15. The apparatus of claim 14 wherein the plate comprises at least one of the following:

a flat portion, a convex portion, or a concave portion.

16. The apparatus of claim 14 wherein the plate has a geometric configuration and is formed of a material selected to allow resonance at desired frequencies.

17. The apparatus of claim 14 wherein the plate comprises one or more channels to optimize stiffness of the plate.

18. The apparatus of claim 14 wherein the one or more channels are designed to reduce acoustic waves generated in unwanted modes.

19. The apparatus of claim 14 wherein the plate couples to each axial driver through at least one tapered force shaft having a narrow end at a junction between the tapered force shaft and the moment arm and a wide end at a junction between the tapered force shaft and the axial driver.

20. The apparatus of claim 14 wherein each axial driver couples to a backing mass, and the backing mass is preloaded with a bolt such that the moment arm experiences a substantially net zero preload force.

21. The apparatus of claim 14 wherein each axial driver couples to a backing mass, and the backing mass is formed of a material selected to compensate for thermal expansion of the housing.

22. An apparatus for generating acoustic waves, comprising:

a housing;

a plate having a moment arm, wherein the plate couples to the housing;

two tapered force shafts coupled to the moment arm, wherein each tapered force shaft has a narrow end and a wide end, and each tapered force shaft couples to the moment arm at the narrow end;

an axial driver coupled to the wide end of each tapered force shaft, wherein each axial driver aligns with a longitudinal axis of the housing;

a backing mass coupled to each axial driver, wherein the backing mass is formed of a material selected to compensate for thermal expansion of the housing; and

a preload bolt coupling each backing mass to the housing such that the moment arm experiences a substantially net zero preload force.