Piezotech LLC

Mahesh Matam

Frans Lautzenhiser

Eric Molz

Patrick Gwin

Pat Gwin

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

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 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

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.

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Zionsville, IN, United States of America

Mahesh Matam