Method and system for measuring azimuthal anisotropy effects using acoustic multipole transducers
First Claim
1. A method, using at least one multipole transducer, for logging a borehole having a longitudinal axis to obtain information for measuring azimuthal anisotropy of a formation traversed by the borehole, including the steps of:
- (a) operating a first transducer disposed in the borehole to generate a first acoustic signal that will propagate into the formation from within the borehole;
(b) detecting an arrival of the first acoustic signal at a second transducer disposed in the borehole, where one of the first and second transducers is a monopole transducer and the other is a quadrupole transducer oriented at a first azimuthal angle relative to the longitudinal axis of the borehole; and
(c) at a location within the borehole, detecting another acoustic arrival, where the arrival detected in this step (c) is associated with a second azimuthal angle relative to the longitudinal axis of the borehole.
1 Assignment
0 Petitions
Accused Products
Abstract
An acoustic borehole well logging method and apparatus for measuring azimuthal anisotropy of a formation traversed by a borehole using at least one multipole transducer. In a preferred embodiment, a dipole wave transmitter and at least one detector sensitive to dipole waves are employed. In an alternative preferred embodiment, a monopole transmitter and at least one multipole detector are employed. In the inventive method, two acoustic wave arrivals are detected, each associated with a different azimuthal orientation relative to the longitudinal axis of the borehole (i.e. each is transmitted by a multipole transmitter oriented at such angle, or is detected by a multipole detector oriented at such angle, or both). The inventive apparatus preferably includes at least one transducer unit including two or more multipole transmitters (or two or more multipole detectors) oriented at different azimuthal angles relative to the tool'"'"'s longitudinal axis.
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Citations
44 Claims
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1. A method, using at least one multipole transducer, for logging a borehole having a longitudinal axis to obtain information for measuring azimuthal anisotropy of a formation traversed by the borehole, including the steps of:
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(a) operating a first transducer disposed in the borehole to generate a first acoustic signal that will propagate into the formation from within the borehole; (b) detecting an arrival of the first acoustic signal at a second transducer disposed in the borehole, where one of the first and second transducers is a monopole transducer and the other is a quadrupole transducer oriented at a first azimuthal angle relative to the longitudinal axis of the borehole; and (c) at a location within the borehole, detecting another acoustic arrival, where the arrival detected in this step (c) is associated with a second azimuthal angle relative to the longitudinal axis of the borehole. - View Dependent Claims (2, 3, 4, 5, 6, 7, 8, 9, 12)
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10. A method, using at least one multipole transducer, for logging a borehole having a longitudinal axis to obtain information for measuring azimuthal anisotropy of a formation traversed by the borehole, including the steps of:
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(a) operating a first transducer disposed in the borehole to generate a first acoustic signal that will propagate into the formation from within the borehole; (b) detecting an arrival of the first acoustic signal at a second transducer disposed in the borehole, where one of the first and second transducers is a monopole transducer having multipole order n=0 and the other is a multipole transducer having multipole order n+2m, where m is a member of the set of integers and half-integer numbers and n+2m>
0, at least one of the transducers defining a first azimuthal angle relative to the longitudinal axis of the borehole;(c) rotating said multipole transducer to define a second azimuthal angle relative to the longitudinal axis of the borehole; (d) operating said first transducer to generate a second acoustic signal azimuthally distinct from said first acoustic signal; and (e) detecting the arrival of the second acoustic signal with the second transducer.
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11. An apparatus for logging a borehole to obtain information for measuring azimuthal anisotropy of a formation traversed by the borehole, including:
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(a) a housing adapted to be suspended in the borehole and having a longitudinal axis; (b) a first monopole transducer having multipole order n=0 mounted in the housing and capable of generating a first acoustic signal that will propagate from within the borehole into the formation; (c) a first multipole receiver, having multipole order n+2m, where n is zero, m is a member of the set of integers and half-integer numbers, and n+2m>
0, and capable of detecting an arrival of the first acoustic signal, said first multipole receiver being mounted in the housing at a first azimuthal angle relative to the longitudinal axis; and(d) a second multipole receiver, having multipole order n+2p, where n is zero, p is a member of the set of integers and half-integer numbers, and n+2p>
0, and capable of detecting an arrival of the first signal, said second multipole receiver being mounted in the housing at a second azimuthal angle relative to the longitudinal axis. - View Dependent Claims (31, 32, 33, 37)
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13. An apparatus for logging a borehole to obtain information for measuring azimuthal anisotropy of a formation traversed by the borehole, including:
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(a) a housing adapted to be suspended in the borehole and having a longitudinal axis; (b) a first multipole transmitter having multipole order n+2m, where n is zero, m is a member of the set of integers and half-integer numbers, and n+2m>
0, said first multipole transmitter being mounted in the housing at a first azimuthal angle relative to the longitudinal axis, and being capable of generating a first acoustic signal that will propagate from within the borehole into the formation;(c) a second multipole transmitter, having multipole order n+2p, where n is zero, p is a member of the set of integers and half-integer numbers, and n+2p>
0, said second multipole transmitter being mounted in the housing at a second azimuthal angle relative to the longitudinal axis, and being capable of generating a second acoustic signal that will propagate from within the borehole into the formation; and(d) a monopole receiver, having multipole order n=0, mounted in the housing at a position spaced along the longitudinal axis from the first transmitter and the second transmitter, and capable of detecting arrivals of the first and second acoustic signals. - View Dependent Claims (14, 34, 35, 36, 38)
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15. An apparatus for logging a borehole to obtain information for measuring azimuthal anisotropy of a formation traversed by the borehole, including:
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(a) a housing adapted to be suspended in the borehole and having a longitudinal axis; (b) a first monopole transducer, having multipole order n=0, mounted in the housing and capable of generating an acoustic signal that will propagate from within the borehole into the formation; (c) a second transducer having multipole order n+2m, where n is zero, m is a member of the set of integers and half-integer numbers, and n+2m>
0, said second transducer being mounted in the housing and capable of detecting an arrival of the acoustic signal; and(d) means for rotating the second transducer azimuthally.
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16. A method, using at least one multipole transducer, for logging a borehole having a longitudinal axis to obtain information for measuring azimuthal anisotropy of a formation traversed by the borehole, including the steps of:
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(a) operating a first transducer disposed in the borehole to generate a first acoustic signal that will propagate into the formation from within the borehole; (b) detecting an arrival of the first acoustic signal at a second transducer disposed in the borehole, where one of the first and second transducers is a dipole transducer and the other is a quadrupole transducer, at least one of the transducers defining a first azimuthal angle relative to the longitudinal axis of the borehole; and (c) at a location within the borehole, detecting another acoustic arrival associated with a second azimuthal angle relative to the longitudinal axis of the borehole. - View Dependent Claims (17, 18, 19, 20, 44)
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21. A method, using at least one multipole transducer, for logging a borehole having a longitudinal axis to obtain information for measuring azimuthal anisotropy of a formation traversed by the borehole, including the steps of:
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(a) operating a first transducer disposed in the borehole to generate a first acoustic signal that will propagate into the formation from within the borehole; (b) detecting an arrival of the first acoustic signal at a second transducer disposed in the borehole, where one of the first and second transducers is a monopole transducer and the other is a dipole transducer, at least one of the transducers defining a first azimuthal angle relative to the longitudinal axis of the borehole; and (c) at a location within the borehole, detecting another acoustic arrival, where the arrival detected in this step (c) is associated with a second azimuthal angle relative to the longitudinal axis of the borehole. - View Dependent Claims (22, 23, 24, 25)
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26. A method, using at least one multipole transducer, for logging a borehole having a longitudinal axis to obtain information for measuring azimuthal anisotropy of a formation traversed by the borehole, including the steps of:
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(a) operating a first transducer disposed in the borehole to generate a first acoustic signal that will propagate into the formation from within the borehole; (b) detecting an arrival of the first acoustic signal at a second transducer disposed in the borehole, where one of the first and second transducers is a monopole transducer and the other is a octopole transducer, at least one of the transducers defining a first azimuthal angle relative to the longitudinal axis of the borehole; and (c) at a location within the borehole, detecting another acoustic arrival, where the arrival detected in this step (c) is associated with a second azimuthal angle relative to the longitudinal axis of the borehole. - View Dependent Claims (27, 28, 29, 30)
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39. An apparatus for logging a borehole to obtain information for measuring azimuthal anisotropy of a formation traversed by the borehole, including:
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(a) a housing adapted to be suspended in the borehole and having a longitudinal axis; (b) a first dipole transducer having mounted in the housing and capable of generating a first acoustic signal that will propagate from within the borehole into the formation; (c) a first multipole receiver, having multipole order n+2m, where n is a one, m is a member of the set of integers and half-integer numbers, and n+2m>
0, and capable of detecting an arrival of the first acoustic signal, said first multipole receiver being mounted in the housing at a first azimuthal angle relative to the longitudinal axis; and(d) a second multipole receiver, having multipole order n+2p, where n is one, p is a member of the set of integers and half-integer numbers, and n+2p>
0, and capable of detecting an arrival of the first signal, said second multipole receiver being mounted in the housing at a second azimuthal angle relative to the longitudinal axis.
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40. An apparatus for logging a borehole to obtain information for measuring azimuthal anisotropy of a formation traversed by the borehole, including:
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(a) a housing adapted to be suspended in the borehole and having a longitudinal axis; (b) a first multipole transmitter having multipole order n+2m, where n is one, m is a member of the set of integers and half-integer numbers, and n+2m>
0, said first multipole transmitter being mounted in the housing at a first azimuthal angle relative to the longitudinal axis, and being capable of generating a first acoustic signal that will propagate from within the borehole into the formation;(c) a second multipole transmitter, having multipole order n+2p, where n is one, p is a member of the set of integers and half-integer numbers, and n+2p>
0, said second multipole transmitter being mounted in the housing at a second azimuthal angle relative to the longitudinal axis, and being capable of generating a second acoustic signal that will propagate from within the borehole into the formation; and(d) a dipole receiver mounted in the housing at a position spaced along the longitudinal axis from the first transmitter and the second transmitter, and capable of detecting arrivals of the first and second acoustic signals.
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41. An apparatus for logging a borehole to obtain information for measuring azimuthal anisotropy of a formation traversed by the borehole, including:
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(a) a housing adapted to be suspended in the borehole and having a longitudinal axis; (b) a first transducer having multipole order n+2m, where n is zero, m is a member of the set of integers and half-integer numbers, and n+2m>
0, said second transducer being mounted in the housing and capable of detecting an arrival of the acoustic signal;(c) a second monopole transducer having multipole order n=0 mounted in the housing and capable of generating an acoustic signal that will propagate from within the borehole into the formation; and (d) means for rotating the first transducer azimuthally.
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42. An apparatus for logging a borehole to obtain information for measuring azimuthal anisotropy of a formation traversed by the borehole, including:
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(a) a housing adapted to be suspended in the borehole and having a longitudinal axis; (b) a first transducer having multipole order n+2m, where n is one, m is a member of the set of integers and half-integer numbers, and n+2m>
0, said second transducer being mounted in the housing and capable of detecting an arrival of the acoustic signal;(c) a second dipole transducer having multipole order n=1 mounted in the housing and capable of generating an acoustic signal that will propagate from within the borehole into the formation; and (d) means for rotating the first and second transducers azimuthally with respect to each other.
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43. A method, using at least one multipole transducer, for logging a borehole having a longitudinal axis to obtain information for measuring azimuthal anisotropy of a formation traversed by the borehole, including the steps of:
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(a) operating a first transducer disposed in the borehole to generate a first acoustic signal that will propagate into the formation from within the borehole; (b) detecting an arrival of the first acoustic signal at a second transducer disposed in the borehole, where one of the first and second transducers is a dipole transducer having multipole order n=1 and the other is a multipole transducer having multipole order n+2m, where m is a member of the set of integers and half-integer numbers and n+2m>
0, at least one of the transducers defining a first azimuthal angle relative to the longitudinal axis of the borehole;(c) rotating at least one of said first and second transducers to define a second azimuthal angle relative to the longitudinal axis of the borehole; (d) operating said first transducer to generate a second acoustic signal azimuthally distinct from said first acoustic signal; and (e) detecting the arrival of the second acoustic signal with the second transducer.
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Specification