Acoustic transducers for tubulars
Acoustic transducers configured with transducer elements disposed on an arch or arcuate shaped member adapted to fit in juxtaposition around a tubular. The arcuate shaped member is adapted with conductors to provide a voltage to the transducer elements. One embodiment uses a metallic arcuate shaped member. Embodiments implemented as sources are used to excite borehole acoustic modes. Some embodiments provide phased array acoustic energy excitation/signal reception. The transducers are covered with a sealer in a liquid-free configuration and shields are used to protect the transducers.
1. A method of producing an acoustic transducer for use on a tubular, comprising:
disposing an arcuate shaped member formed as a sector of a cylindrical surface of revolution on the tubular;
disposing a plurality of acoustic transducer elements on the member to receive or emit acoustic energy, the arcuate shaped member being configured to provide voltage to the elements;
configuring a first conductor in contact with first planar surfaces of the transducer elements;
configuring a second conductor in contact with second planar surfaces of the transducer elements;
the transducer elements on the first planar surfaces electrically isolated from the transducer elements on the second planar surfaces;
configuring a subset of the plurality of transducer elements disposed on the member for activation with a voltage of different polarity in relation to another element disposed thereon; and
sealing the member and transducer elements to form a liquid-free acoustic transducer,
wherein the tubular has an exterior surface configured for contact with well-bore environment, and the acoustic transducer is configured for placement around the exterior surface of the tubular in contact with well-bore environment.
2. An acoustic transducer for use on a tubular for subsurface disposal, comprising:
an arcuate shaped member formed as a sector of a cylindrical surface of revolution for disposal on the tubular;
a plurality of acoustic transducer elements disposed on the member to receive or emit acoustic energy;
the arcuate shaped member configured to provide voltage to the elements;
a first conductor in contact with first planar surfaces of the transducer elements;
a second conductor in contact with second planar surfaces of the transducer elements;
the transducer elements on the first planar surfaces electrically isolated from the transducer elements on the second planar surfaces;
a subset of the plurality of transducer elements disposed on the member configured for activation with a voltage of different polarity in relation to another element disposed thereon; and
the member and transducer elements being sealed to form a liquid-free acoustic transducer,
wherein the tubular has an exterior surface configured for contact with well-bore environment, and the acoustic transducer is configured for placement around the exterior surface of the tubular in contact with well-bore environment.
3. The transducer of claim 2 , wherein the arcuate shaped member is adapted for placement around the exterior surface of a tubular.
4. The transducer of claim 2 , wherein the acoustic transducer elements are adapted to emit acoustic energy.
5. The transducer of claim 2 , wherein the acoustic transducer elements are adapted to receive acoustic energy.
6. The transducer of claim 2 , wherein the arcuate shaped member is formed of a substantially nonconductive material.
7. The transducer of claim 2 , the arcuate shaped member further comprising a heavy-mass material disposed adjacent to at least one transducer element to attenuate acoustic energy propagation near a concave surface of said arcuate shaped member.
8. The transducer of claim 7 , wherein the heavy-mass material consists of Tungsten.
9. The transducer of claim 7 , wherein the heavy-mass material is electrically conductive.
10. The transducer of claim 2 , wherein said first and second conductors each comprise a series of conductors forming a mesh.
11. The transducer of claim 2 , the arcuate shaped member configured to provide a subset of the transducer elements disposed thereon with voltage in a timed sequence.
12. The transducer of claim 2 , comprising two arcuate shaped members, each member forming half of a cylindrical surface of revolution for disposal on the tubular and having a plurality of acoustic transducer elements disposed thereon for selective activation to receive or emit acoustic energy.
13. The transducer of claim 2 , comprising four arcuate shaped members, each member forming a quadrant of a cylindrical surface of revolution for disposal on the tubular and having a plurality of acoustic transducer elements disposed thereon for selective activation to receive or emit acoustic energy.
14. The transducer of claim 2 , the arcuate shaped member configured to provide the transducer elements disposed thereon with a multiphase voltage.
15. The transducer of claim 2 , wherein the arcuate shaped member is electrically conductive.
16. The transducer of claim 15 , wherein the arcuate shaped member provides a first voltage to first planar surfaces of the transducer elements disposed thereon and a conductor provides a second voltage to second planar surfaces of the transducer elements disposed thereon.
17. The transducer of claim 2 , wherein the transducer is configured to operate in monopole, dipole or quadrupole mode.
18. The transducer of claim 2 , wherein the transducer is configured for placement around the exterior surface of a wireline tubular.
19. The transducer of claim 2 , wherein the transducer is configured for placement around the exterior surface of a while-drilling tubular.