Guided acoustic waves isolation system for downhole applications

• US 9,581,708 B2
• Filed: 09/04/2014
• Issued: 02/28/2017
• Est. Priority Date: 09/04/2014
• Status: Active Grant

• Current Assignee: Baker Hughes Incorporated (Baker Hughes Company)
• Original Assignee: Baker Hughes Incorporated (Baker Hughes Company)
• Inventors: Khajeh, Ehsan, Steinsiek, Roger R., Green, Ryan D.
• Primary Examiner(s): Murphy, Daniel L
• Application Number:
  US14/477,316
• Publication Number:
  US 20160070014A1
• Time in Patent Office: 908 Days
• Field of Search: 367/25
• US Class Current: 1/1
• CPC Class Codes: G01V 1/306 for determining physical properties of the subsurface, e.g. impedance, porosity or attenuation profiles
• CPC Class Codes: G01V 1/50 Analysing data
• CPC Class Codes: G01V 1/52 Structural details
• CPC Class Codes: G01V 2210/1299 Subsurface, e.g. in borehole or below weathering layer or mud line
• CPC Class Codes: G01V 2210/1429 Subsurface, e.g. in borehole or below weathering layer or mud line

Abstract

An apparatus for estimating a property of a subsurface material includes a carrier configured to convey an acoustic wave guide though a borehole. The acoustic wave guide includes an acoustic plate configured to guide an acoustic wave along a path of the plate and an acoustic reservoir coupled to the acoustic plate and at least partially surrounding the acoustic plate. The acoustic reservoir has a mass greater than the mass of the acoustic plate and is configured to absorb acoustic wave leakage from the acoustic plate. A first acoustic transducer is coupled to the acoustic plate and configured to transmit an acoustic wave along the path. A second acoustic transducer is coupled to the acoustic plate and configured to receive the acoustic wave that travels along the path. A controller is configured to operate the first acoustic transducer and the second acoustic transducer in order to estimate the property.

Claims

1. An apparatus for estimating a property of a subsurface material, the apparatus comprising:

a carrier configured to be conveyed through a borehole penetrating the earth;

an acoustic wave guide coupled to the carrier, the acoustic wave guide comprising an acoustic plate configured to guide an acoustic wave along a lateral path of the plate on which the subsurface material is disposed and an acoustic reservoir coupled to the acoustic plate and at least partially surrounding the acoustic plate, the acoustic reservoir having a mass greater than the mass of the acoustic plate and being configured to absorb leakage of the acoustic wave from the acoustic plate;

a first acoustic transducer coupled to the acoustic plate and configured to transmit an acoustic wave along the path;

a second acoustic transducer coupled to the acoustic plate and configured to receive the acoustic wave that travels along the path; and

a controller configured to operate the first acoustic transducer and the second acoustic transducer in order to estimate the property.

2. The apparatus according to claim 1, wherein the acoustic plate is rectangular and the path is a longitudinal axis of the acoustic plate.

3. The apparatus according to claim 2, wherein a length of the acoustic plate is at least ten times a width of the acoustic plate.

4. The apparatus according to claim 3, wherein a thickness of the acoustic plate is less than the width of the acoustic plate.

5. The apparatus according to claim 1, wherein a top surface of the acoustic reservoir at least partially surrounding a top surface of the acoustic plate is curved and configured to reflect leakage of the acoustic signal from the acoustic plate that is not absorbed by the acoustic reservoir, wherein the curved top surface is configured to reflect the leakage away from the acoustic plate.

6. The apparatus according to claim 1, wherein the acoustic wave guide defines a first recess between a top surface of the acoustic plate and the acoustic reservoir, the first recess at least partially surrounding the acoustic plate, wherein the first recess is defined by the top surface of the acoustic plate and a surface of the acoustic reservoir that opposes the top surface of the acoustic plate.

7. The apparatus according to claim 6, wherein the acoustic reservoir defines a second recess laterally surrounding at least part of the first recess.

8. The apparatus according to claim 1, wherein the acoustic reservoir comprises a curved edge comprises a curved edge above a top surface of the acoustic plate, the curved edge being configured to reflect acoustic wave leakage away from the acoustic plate.

9. The apparatus according to claim 1, wherein the acoustic reservoir defines a plurality of holes configured to interface with a fastener configured to secure the acoustic wave guide to the carrier.

10. The apparatus according to claim 1, wherein the acoustic wave guide is one monolithic material.

11. The apparatus according to claim 1, wherein the acoustic wave guide comprises at least one of stainless steel, titanium, and Inconel.

12. The apparatus according to claim 1, wherein the second acoustic transducer comprises two acoustic transducers that are coupled to the acoustic plate and configured to receive the acoustic signal that travels along the path.

13. The apparatus according to claim 1, wherein the carrier comprises a wireline or a drill tubular.

14. A method for estimating a property of a subsurface material, the method comprising:

conveying a carrier through a borehole penetrating the earth, the carrier being coupled to an acoustic wave guide comprising an acoustic plate configured to guide an acoustic wave along a lateral path of the acoustic plate on which the subsurface material is disposed and an acoustic reservoir coupled to the acoustic plate and at least partially surrounding the acoustic plate, the acoustic reservoir having a mass greater than the mass of the acoustic plate and being configured to absorb leakage of the acoustic wave from the acoustic plate;

transmitting an acoustic wave along the path of the acoustic plate using a first acoustic transducer;

receiving the acoustic wave that travels along the path using a second acoustic transducer; and

estimating the property using a controller that operates the first acoustic transducer and the second acoustic transducer.

15. The method according to claim 14, further comprising absorbing leakage of the acoustic wave that leaks from the acoustic plate using the acoustic reservoir.

16. The method according to claim 15, further comprising reflecting leakage of the acoustic wave that is not absorbed by the acoustic reservoir away from the acoustic plate using a curved top surface of the acoustic reservoir.

17. The method according to claim 14, further comprising acoustically isolating the acoustic plate from the acoustic reservoir using a first recess between a top surface of the acoustic plate and the acoustic reservoir, the first recess at least partially surrounding the acoustic plate, wherein the first recess is defined by the top surface of the acoustic plate and a surface of the acoustic reservoir that opposes the top surface of the acoustic plate.

18. The method according to claim 17, further comprising isolating the acoustic plate from the acoustic reservoir using a second recess laterally surrounding at least part of the first recess.