Piezotech LLC

Frans Lautzenhiser

James Dallas

Mahesh Matam

Eric Molz

Ramesh Janardhanam

Michael H Phillips

Patrick Gwin

Pat Gwin

Fredric Bernard Grossman

A single critically damped acoustic stack yields a wide frequency range as an acoustic transmitter or as an acoustic transducer having particular use in well integrity determination. The critically damped present acoustic stack utilizes a plurality of stacked acoustic elements such as piezoelectric ceramics that are energized in two manners, providing different center frequencies, each producing a respective center frequency of 100% bandwidth to yield an acoustic stack having a total bandwidth exceeding the bandwidth of an acoustic element or the bandwidth of the plurality of acoustic elements. One manner of energizing is to pulse only one of the acoustic elements. The other manner is to pulse a first acoustic element then pulse a second acoustic element after a delay equal to the amount of time it takes for the first pulse to reach the face of the second acoustic element. The acoustic stack is primarily used in pulse-echo analysis of metal casing wall thickness and cement bond quality detection of wells.

Enhanced bandwidth transducer method for well integrity measurement

A system, method and device are provided for detecting the presence of, and/or obtain information about, a replaceable component for a host system. A host system has an ultrasonic transducer or transducer pair that detects the presence of, and/or obtains information about, a replaceable component for a host system through receipt or non-receipt of an ultrasonic signal. The replaceable component includes a key or other feature that either allows the transmission or reflection of a transmitted ultrasonic signal, or which does not allow the reception or reflection of the transmitted ultrasonic signal, depending on the host configuration.

Ultrasonic identification of replaceable component for host system

Low frequency pulse-echo ultrasonic transducers are provided especially suited for use in downhole cement bond evaluation, but usable for various applications. One frequency pulse-echo ultrasonic transducer comprises a transducer stack having alternating layers of a piezoceramic element and an ultrasonic attenuating element that is preferably acoustic impedance matched to the piezoceramic elements in order to reduce the Q of the transducer stack. Another low frequency pulse-echo ultrasonic transducer comprises an assembly having the present transducer stack disposed on an acoustic attenuating backing and a front face. Yet another low frequency pulse-echo ultrasonic transducer comprises a transducer composite made from a lead metaniobate. Still another frequency pulse-echo ultrasonic transducer comprises a composite stack. A further low frequency pulse-echo ultrasonic transducer comprises a composite stack, wherein multiple drive elements allow driving individual elements at different times. The transducers may be driven in a multiple-pulse time delayed manner.

Low frequency broad band ultrasonic transducers

A system, method and device are provided for detecting the presence of, and/or obtain information about, a replaceable component for a host system. A host system has an ultrasonic transducer pair that detects the presence of, and/or obtains information about, a replaceable component for a host system through receipt or non-receipt of an ultrasonic signal. The replaceable component includes a key or other feature that either allows the transmission of a transmitted ultrasonic signal, or which does not allow the reception of the transmitted ultrasonic signal, depending on the host configuration.

A single critically damped acoustic stack yields a wide frequency range as an acoustic transmitter or as an acoustic transducer having particular use in well integrity determination. The critically damped present acoustic stack utilizes a plurality of stacked acoustic elements such as piezoelectric ceramics that are energized in two manners, providing different center frequencies; each producing a respective center frequency of 100% bandwidth to yield an acoustic stack having a total bandwidth exceeding the bandwidth of an acoustic element or the bandwidth of the plurality of acoustic elements. One manner of energizing is to pulse only one of the acoustic elements. The other manner is to pulse a first acoustic element the pulse a second acoustic element after a delay equal to the amount of time it takes for the first pulse to reach the face of the second acoustic element. The acoustic elements are bonded together and onto a critically damped backing of tungsten. The assembly is retained in a housing that is preferably made of PEEK. The acoustic stack is primarily used in pulse-echo analysis of metal casing wall thickness and cement bond quality detection of wells.

Enhanced bandwidth transducer for well integrity measurement

An insulated sounder assembly may include: a) a sounder cup having a bottom and a sidewall; b) a piezoelectric element positioned in the bottom of the cup; c) a potting layer within the sounder cup and spaced apart from the piezoelectric element so that the potting layer contacts the cup sidewall for a distance of at least 3 mm around the entire circumference of the cup, and so that a gap exists between the piezoelectric element and the potting layer, with the gap being sufficient to allow vibration of the piezoelectric element in the sounder cup without restriction by the potting layer; and d) an electrical contact wire attached to the piezoelectric element to provide a voltage to the piezoelectric element, wherein the electrical contact wire passes through the potting layer so that at least 3 mm of bare wire is completely embedded in said potting layer.

Sounder assembly for explosive environment

A piezoceramic pulse-echo acoustic transducer includes protection layers for the piezoceramic that are tuned to the piezoceramic so as to optimize pulse-echo signal response (i.e. greater output signal bandwidth and increased return signal sensitivity). The protection layers are tuned to the piezoceramic via material selection and thickness. The acoustic transducer has a backing, a piezoceramic adjacent the backing, an intermediate protection layer adjacent the piezoceramic, and a front protection layer adjacent the intermediate protection layer and opposite the piezoceramic. The front and intermediate protection layers are tuned to the piezoceramic via their acoustic impedance such that the acoustic impedance of the intermediate layer is greater than the acoustic impedance of the piezoceramic and of the front protection layer. The acoustic impedance of the front protection layer is less than the acoustic impedance of the piezoceramic.

Pulse-echo acoustic transducer

A device for acoustic measuring in a medium in a borehole such as velocity of sound in the medium or velocity of the medium, includes at least a first acoustic array situated in a first, slanted sidewall of a measuring area and operating to emit a series of acoustic waveforms across a measuring area. In one form, the device includes a second acoustic array situated in a second, slanted sidewall of the measuring area and operating to receive an acoustic signal resulting from the emitted series of acoustic waveforms or to receive said acoustic signal and emit a second series of acoustic waveforms. A the processor measures a time between when a predefined portion of one of the series of acoustic waveforms was emitted and when a predefined portion of the received acoustic signal corresponding to the predefined portion of one of the series of acoustic waveforms is received by the acoustic receiver, and correlates the measured time to a reference time, then outputs a correlation factor for determining the velocity of sound in the medium in the measuring area. The processor may also calculate transit time for the two emitted acoustic signals or echoes from the first emitted acoustic signals to determine medium flow velocity.

System and device for acoustic measuring in a medium

A buzzer includes a piezoelectric diaphragm and a housing enclosing the diaphragm and defining a resonating chamber. The chamber includes a sound port and has an optimal resonating frequency fat a temperature T defined by f=(v/2&#x3c0;)(&#x221a;(A/vL)) were vis the velocity of sound waves in air at a temperature T, A is the effective area of the sound port, vis the volume of the resonating chamber, and L is the effective length of the sound port. A temperature compensating member moves in response to changes in temperature to change the value of &#x221a;(A/voL) at a rate and in a manner that balances the change in 1/vacross that same temperature range, thereby reducing changes in the product (v/2&#x3c0;)(&#x221a;(A/vL)) and consequently reducing any changes that would otherwise occur in facross that temperature range, thereby holding the value of fsubstantially constant across the temperature range.

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Zionsville, IN, United States of America

Frans Lautzenhiser