Acoustic velocity measurements using tilted transducers

Patent metadata

Field	Value
Publication number	US-9631480-B2
Application number	US-200913264336-A
Country	US
Kind code	B2
Filing date	Jul 16, 2009
Priority date	May 11, 2009
Publication date	Apr 25, 2017
Grant date	Apr 25, 2017

Abstract

Apparatus, systems, and methods may operate to emit acoustic pulses into a drilling fluid in a well bore, using a first acoustic transducer in a downhole tool, and detecting the acoustic pulses after reflection from the wall of the well bore, using a second acoustic transducer in the downhole tool. The faces of the first and second acoustic transducers are non-parallel. Further activities include emitting additional acoustic pulses into the drilling fluid using the second acoustic transducer, and detecting them using the second acoustic transducer. The acoustic velocity of the drilling fluid can be determined based on respective travel times. Additional apparatus, systems, and methods are described.

First claim

What is claimed is:

1. A method comprising:
emitting a first acoustic pulse into a drilling fluid in a well bore, using a first acoustic transducer in a downhole tool, wherein a face of the first acoustic transducer is at an angle that is not parallel to an outer surface of the downhole tool;
detecting the first acoustic pulse after the first acoustic pulse has traveled through the drilling fluid and reflected off a wall of the well bore, using a second acoustic transducer in the downhole tool, wherein a face of the second acoustic transducer is approximately parallel with the outer surface of the downhole tool;
emitting a second acoustic pulse into the drilling fluid in the well bore, using the second acoustic transducer;
detecting the second acoustic pulse after the second acoustic pulse has traveled through the drilling fluid and reflected off the wall of the well bore, using the second acoustic transducer; and
determining an acoustic velocity of the drilling fluid based on a travel time of the first acoustic pulse and a travel time of the second acoustic pulse.

2. The method of claim 1 , further comprising:
emitting a third acoustic pulse into the drilling fluid in the well bore, using a third acoustic transducer in the downhole tool, wherein a face of the third acoustic transducer is at an angle that is not parallel to the outer surface of the downhole tool;
detecting the third acoustic pulse after the third acoustic pulse has traveled through the drilling fluid and reflected off the wall of the well bore, using the second acoustic transducer; and
determining the acoustic velocity of the drilling fluid based on a travel time of the third acoustic pulse.

3. The method of claim 1 , wherein the first acoustic transducer and the second acoustic transducer are part of a same dual-element transducer.

4. The method of claim 3 , wherein the first acoustic transducer and the second acoustic transducer are separated a distance L, wherein an acoustic insulation is between the first acoustic transducer and the second acoustic transducer.

5. The method of claim 4 , wherein a material is between the second acoustic transducer and a face of the outer surface of the downhole tool.

6. The method of claim 5 , wherein the material has an acoustic impedance that is approximately equal to an acoustic impedance of the drilling fluid.

7. An apparatus comprising:
a first acoustic transducer disposed on a downhole tool, wherein a face of the first acoustic transducer is at an angle that is not parallel to an outer surface of the downhole tool, wherein the first acoustic transducer is to emit a first acoustic pulse into a drilling fluid in a well bore; and
a second acoustic transducer disposed on the downhole tool, wherein a face of the second acoustic transducer is approximately parallel with the outer surface of the downhole tool, wherein the second acoustic transducer is to detect the first acoustic pulse after the first acoustic pulse has traveled through the drilling fluid and reflected off a wall of the well bore, wherein the second acoustic transducer is to emit a second acoustic pulse into the drilling fluid in the well bore, and wherein the second acoustic transducer is to detect the second acoustic pulse after the second acoustic pulse has traveled through the drilling fluid and reflected off the wall of the well bore.

8. The apparatus of claim 7 , further comprising a processor element to measure an acoustic velocity of the drilling fluid based on a travel time of the first acoustic pulse and a travel time of the second acoustic pulse.

9. The apparatus of claim 7 , further comprising a processor element to measure an acoustic velocity of the drilling fluid based on a travel time of the first acoustic pulse and a travel time of the second acoustic pulse if the acoustic velocity is within a predetermined range of a moving-average speed for measured acoustic velocities.

10. The apparatus of claim 7 , further comprising a third acoustic transducer to emit a third acoustic pulse into the drilling fluid in the well bore, wherein a face of the third acoustic transducer is at an angle that is not parallel to the outer surface of the downhole tool.

11. The apparatus of claim 10 , wherein the second acoustic transducer is to detect the third acoustic pulse after the third acoustic pulse has traveled through the drilling fluid and reflected off the wall of the well bore.

12. The apparatus of claim 11 , further comprising a processor element to measure an acoustic velocity of the drilling fluid based on a travel time of the first acoustic pulse, a travel time of the second acoustic pulse and a travel time of the third acoustic pulse.

13. A system comprising:
a drill string having a downhole tool, wherein the downhole tool comprises,
a first acoustic transducer, wherein a face of the first acoustic transducer is at an angle that is not parallel to an outer surface of the downhole tool, wherein the first acoustic transducer is to emit a first acoustic pulse into a drilling fluid in a well bore; and
a second acoustic transducer, wherein a face of the second acoustic transducer is approximately parallel with the outer surface of the downhole tool, wherein the second acoustic transducer is to detect the first acoustic pulse after the first acoustic pulse has traveled through the drilling fluid and reflected off a wall of the well bore, wherein the second acoustic transducer is to emit a second acoustic pulse into the drilling fluid in the well bore, and wherein the second acoustic transducer is to detect the second acoustic pulse after the second acoustic pulse has traveled through the drilling fluid and reflected off the wall of the well bore.

14. The system of claim 13 , wherein the first acoustic transducer and the second acoustic transducer are part of a same dual-element transducer.

15. The system of claim 14 , wherein the first acoustic transducer and the second acoustic transducer are separated by a distance L, wherein an acoustic insulation is between the first acoustic transducer and the second acoustic transducer.

16. The system of claim 15 , wherein a material is between the second acoustic transducer and a face of the outer surface of the downhole tool.

17. The system of claim 16 , wherein the material has an acoustic impedance that is approximately equal to an acoustic impedance of the drilling fluid.

18. The system of claim 13 , wherein the downhole tool further comprises a processor element to measure an acoustic velocity of the drilling fluid based on a travel time of the first acoustic pulse and a travel time of the second acoustic pulse.

19. The system of claim 13 , wherein the downhole tool further comprises a processor element to measure an acoustic velocity of the drilling fluid based on a travel time of the first acoustic pulse and a travel time of the second acoustic pulse if the acoustic velocity is within a predetermined range of a moving-average speed for measured acoustic velocities.

20. The system of claim 13 , wherein the downhole tool further comprises a third acoustic transducer to emit a third acoustic pulse into the drilling fluid in the well bore, wherein a face of the third acoustic transducer is at an angle that is not parallel to the outer surface of the downhole tool.

21. The system of claim 13 , wherein the second acoustic transducer is to detect the third acoustic pulse after the third acoustic pulse has traveled through the drilling fluid and reflected off the wall of the well bor

Assignees

• Cooper Paul
• Sherrill Kristopher V
• Ortiz Ricardo
• Flores Daniel
• Mandal Batakrishna
• Halliburton Energy Services Inc

Inventors

• Cooper Paul
• Sherrill Kristopher V
• Ortiz Ricardo
• Flores Daniel
• Mandal Batakrishna

Classifications

• E21B47/107 Primary

  using acoustic means · CPC title

• E21B47/101 Primary

  Fixed Constructions · mapped topic