Combined electro-magnetic acoustic transducer
First Claim
1. An apparatus configured for use with an electrically conducting material, the tool comprising:
- (a) a magnet assembly including a plurality of magnets with alternating polarization in a direction substantially orthogonal to a first direction of a body of the electrically conducting material;
(b) a first conductor configured to carry a first current in a direction substantially parallel to the first direction and generate a shear wave in the body upon passage of the first current;
(c) a second conductor configured to carry a second current in a direction substantially orthogonal to the first direction and substantially orthogonal to the direction of polarization of the plurality of magnets and generate a Lamb wave upon passage of the second current;
(d) a receiving transducer configured to produce signals responsive to the generated shear wave and the generated Lamb wave; and
(e) a processor configured to;
(I) use the produced signals to estimate a property of the received shear wave and the received Lamb wave, and(II) record the estimated property on a suitable medium.
2 Assignments
0 Petitions
Accused Products
Abstract
A combined electromagnetic acoustic transducer (EMAT) is disclosed adapted to generate both SH-type acoustic waves and LAMB-type acoustic waves in a conductive casing, surroundings of which are to be analyzed. The transducer comprises one magnet assembly and two RF coils implemented as multi-layer printed circuit board. Each coil is used to generate or receive acoustic signals of one wave type. Compared to using two single-wave-type transducers the combined EMAT significantly reduces total attraction force to the casing and, correspondingly, simplifies mechanics of the measurement tool. It is emphasized that this abstract is provided to comply with the rules requiring an abstract which will allow a searcher or other reader to quickly ascertain the subject matter of the technical disclosure. It is submitted with the understanding that it will not be used to interpret or limit the scope or meaning of the claims.
79 Citations
20 Claims
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1. An apparatus configured for use with an electrically conducting material, the tool comprising:
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(a) a magnet assembly including a plurality of magnets with alternating polarization in a direction substantially orthogonal to a first direction of a body of the electrically conducting material; (b) a first conductor configured to carry a first current in a direction substantially parallel to the first direction and generate a shear wave in the body upon passage of the first current; (c) a second conductor configured to carry a second current in a direction substantially orthogonal to the first direction and substantially orthogonal to the direction of polarization of the plurality of magnets and generate a Lamb wave upon passage of the second current; (d) a receiving transducer configured to produce signals responsive to the generated shear wave and the generated Lamb wave; and (e) a processor configured to; (I) use the produced signals to estimate a property of the received shear wave and the received Lamb wave, and (II) record the estimated property on a suitable medium. - View Dependent Claims (2, 3, 4, 5, 6, 7, 8, 9)
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10. A method of generating acoustic waves in an electrically conducting material, the method comprising:
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(a) providing a magnet assembly including a plurality of magnets with alternating polarization in a direction substantially orthogonal to a first direction of a body of the electrically conducting material; (b) conveying a first current in a direction substantially parallel to the first direction to generate a shear wave in the electrically conducting material; (c) conveying a second current in a direction substantially orthogonal to the first direction and substantially orthogonal to the direction of polarization of the plurality of magnets to generate a Lamb wave; (d) producing signals responsive to the generated shear wave and the generated Lamb wave at a receiving transducer; (e) estimating a property of the received shear wave and the received Lamb wave from the produced signals, and (f) recording the estimate property on a suitable medium. - View Dependent Claims (11, 12, 13, 14, 15, 16, 17, 18)
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19. A computer-readable medium for use with a tool for evaluating an electrically conducting material, the tool comprising:
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(a) a magnet assembly including a plurality of magnets with alternating polarization in a direction substantially orthogonal to a first direction of a body of the electrically conducting material; (b) a first conductor configured to carry a first current in a direction substantially parallel to the first direction and generate a shear wave in the body upon passage of the first current; (c) a second conductor configured to carry a second current in a direction substantially orthogonal to the first direction and substantially orthogonal to the direction of polarization of the plurality of magnets and generate a Lamb wave upon passage of the second current; and (d) a receiving transducer configured to produce signals responsive to the generated shear wave and the generated Lamb wave; the medium comprising instructions which enable a processor to; (e) estimate a velocity of the generated shear wave and the generated Lamb wave from the produced signals; and (f) record the estimated velocities on a suitable medium. - View Dependent Claims (20)
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Specification