摘要:
In one aspect, the disclosure provides an apparatus that includes an acoustic transducer, and a backing coupled to the transducer, wherein the backing includes solid grains with fluid between the grains.
摘要:
In one aspect, the disclosure provides an apparatus that includes an acoustic transducer, and a backing coupled to the transducer, wherein the backing includes solid grains with fluid between the grains.
摘要:
An acoustic transducer assembly includes: a carrier configured to be disposed in an earth formation, the carrier having a carrier axis; an array of transducer elements forming at least a semicircular shape, the array configured to emit acoustic signals in a radial direction relative to the carrier axis; and a circuit coupled to the array and configured to actuate a subset of the transducer elements and emit an acoustic beam therefrom, the circuit configured to actuate the subsets as a phased array to electronically rotate the acoustic beam about the carrier axis.
摘要:
A transducer assembly for downhole imaging includes a 1-3 Piezoelectric composite transducer of high Q ceramic rods in a polymer matrix. The assembly also includes a Teflon® window, a fluid-filled cavity adjacent to the window, and impedance matching material between the composite transducer and the fluid. The transducer is positioned to reduce the reverberation time.
摘要:
A stop collar assembly used for axially securing and/or to resist axial sliding of a downhole tool device. The assembly provided on a housing of the downhole tool and includes a generally annular ring having an inner circumference beveled outward proximate to the ring edge. A clamp ring having a raised portion on its outer surface is disposed adjacent and substantially coaxial with the annular ring. Pushing the annular ring against the clamp ring compresses the clamp ring onto the housing to resist axial sliding of the annular ring.
摘要:
Measurements made by a transducer assembly for downhole imaging are affected by reverberations between the transducer and the window on the outside of the assembly. The reverberations result in a stationary noise on the image. Hardware solutions to improve signal-to-noise ratio includes using a composite transducer, adjusting the distance between the transducer and the window. SNR can also be improved by processing techniques that include stacking, fitting a sinusoid to the reverberation, by envelope peak detection, and by applying a notch filter.
摘要:
A transducer assembly for downhole imaging includes a 1-3 Piezoelectric composite transducer of high Q ceramic rods in a polymer matrix. The assembly also includes a Teflon® window, a fluid-filled cavity adjacent to the window, and impedance matching material between the composite transducer and the fluid. The transducer is positioned to reduce the reverberation time.
摘要:
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.
摘要:
The signal-to-noise ratio of televiewer signals from a rotary sidewall acoustic-beam scanner is improved by replacing the volume of borehole drill fluid that lies in the path of the acoustic beam with a solid medium characterized by a lower coefficient of attenuation than that of the drill fluid.
摘要:
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.