Acoustic sensor for downhole measurement tool
AssigneePathFinder Energy Services, Inc.
InventorElan Yogeswaren
Life of this patent
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Abstract
An acoustic sensor for use in a downhole measurement tool is provided. The acoustic sensor includes a piezo-composite transducer element. In various exemplary embodiments, the acoustic sensor further includes a composite backing layer, at least one matching layer, and a barrier layer deployed at an outermost surface of the sensor. Exemplary embodiments of this invention may advantageously withstand the extreme temperatures, pressures, and mechanical shocks frequent in downhole environments and thus may exhibit improved reliability. Exemplary embodiment of this invention may further provide improved signal to noise characteristics. Methods for fabricating acoustic sensors and downhole measurement tools are also provided.
Claims22
A downhole measurement tool, comprising:
- a substantially cylindrical tool body having a cylindrical axis;
- at least one acoustic sensor deployed on the tool body, the acoustic sensor including a piezo-composite transducer element with anterior and posterior faces, the piezo-composite transducer in electrical communication with an electronic control module via conductive electrodes disposed on each of said faces;
- and
- the piezo-composite transducer element including regions of piezoelectric material deployed in a matrix of a substantially non piezoelectric material, the regions extending through a thickness of the transducer element in at least one dimension, the polymeric material having a glass transition temperature of greater than about 250 degrees C.
An acoustic sensor, comprising:
- a piezo-composite transducer element including regions of piezoelectric material deployed in a matrix of a substantially non piezoelectric polymeric material, the regions extending through a thickness of the transducer element in at least one dimension, the polymeric material having a glass transition temperature of greater than about 250 degrees C.;
- the piezoelectric material having a Curie temperature greater than or equal to about 250 degrees C.;
- the piezo-composite transducer element including conductive electrodes disposed on first and second faces thereof;
- and
- the acoustic sensor being configured for use in a downhole measurement tool.
A method for fabricating a downhole measurement tool, the method comprising:
- (a) providing a substantially cylindrical tool body having an electronic control module, the tool body being couplable with a drill string;
- (b) providing at least one acoustic sensor including a piezo-composite transducer element with anterior and posterior faces, the piezo-composite transducer element including regions of piezoelectric material deployed in a matrix of substantially non piezoelectric polymeric material, the regions extending through a thickness of the transducer element in at least one dimension, the polymeric material having a glass transition temperature of greater than about 250 degrees C., the piezo-composite transducer element further including conductive electrodes disposed on each of said faces;
- (c) deploying the at least one acoustic sensor on the tool body in electrical communication with the electronic control module via said conductive electrodes, the at least one acoustic sensor operable to transmit and receive acoustic signals in a borehole.
Dependencies are inferred from the claim text.