# US 10,481,288 B2 · Ultrasonic transducer with improved backing element > Agents: this data is available as JSON from the patentgrep API and MCP server — see https://patentgrep.com/llms.txt - Number: US 10,481,288 B2 - Document ID: US10481288B2 - Status: Granted - Kind: B2 - Application number: 15/511,936 - Filed: 2015-10-02 - Published: 2017-10-19 - Granted: 2019-11-19 - Earliest claimed: 2015-10-02 - Assignees: Halliburton Energy Services, Inc. - Applicants: Halliburton Energy Services, Inc. - Inventors: Chung Chang; Jing Jin; Yao Ge - Web page: https://patentgrep.com/patent/US10481288B2 ## CPC - G01V 1/44: using generators and receivers in the same well (G01V1/52 takes precedence) - B06B 1/0644: {using a single piezoelectric element (B06B1/0688 takes precedence)} - B06B 1/0685: {on the back only of piezoelectric elements} - E21B 47/005: Monitoring or checking of cementation quality or level - E21B 47/007: Measuring stresses in a pipe string or casing (for locating blocked portions of pipes E21B47/09) - E21B 47/085: using radiant means, e.g. acoustic, radioactive or electromagnetic - E21B 47/095: by detecting an acoustic anomalies, e.g. using mud-pressure pulses - E21B 49/00: Testing the nature of borehole walls; Formation testing; Methods or apparatus for obtaining samples of soil or well fluids, specially adapted to earth drilling or wells - G01V 1/52: Structural details - G01V 1/523: {Damping devices} - G10K 11/002: {Devices for damping, suppressing, obstructing or conducting sound in acoustic devices (G10K1/06 - G10K1/10 take precedence; for electro-mechanical transducers for communication H04R3/002)} - G01V: GEOPHYSICS; GRAVITATIONAL MEASUREMENTS; DETECTING MASSES OR OBJECTS; TAGS (means for indicating the location of accidentally buried, e.g. snow-buried, persons A63B29/02) - B06B: METHODS OR APPARATUS FOR GENERATING OR TRANSMITTING MECHANICAL VIBRATIONS OF INFRASONIC, SONIC, OR ULTRASONIC FREQUENCY, {e.g.} FOR PERFORMING MECHANICAL WORK IN GENERAL (for particular applications, see the relevant subclasses, e.g. B07B1/40, B23Q17/12, B24B31/06; measurement of mechanical vibrations G01H; in direction finding, locating, distance or velocity measuring G01S; {generating seismic energy G01V1/02}; control of mechanical vibrations in general G05D; sound-producing devices, e.g. bells, sirens, whistles G10K, {e.g. methods or devices for transmitting, conducting, or directing sound in general G10K11/00}; generation of electrical oscillations H03B; electromechanical resonators in general H03H; electromechanical transducers {for communication techniques, e.g. microphones, speakers} H04R) - E21B: EARTH OR ROCK DRILLING; OBTAINING OIL, GAS, WATER, SOLUBLE OR MELTABLE MATERIALS OR A SLURRY OF MINERALS FROM WELLS - G10K: SOUND-PRODUCING DEVICES; METHODS OR DEVICES FOR PROTECTING AGAINST, OR FOR DAMPING, NOISE OR OTHER ACOUSTIC WAVES IN GENERAL; ACOUSTICS NOT OTHERWISE PROVIDED FOR ## Abstract In accordance with embodiments of the present disclosure, systems and methods for improving performance of ultrasonic transducers, particularly those used in borehole environments, are provided. The disclosed ultrasonic transducers all feature a backing element that is a ceramic backing material. The ceramic backing material may include a solid piece of ceramic material that is disposed on a back end of a piezoelectric element used in the ultrasonic transducer. The disclosed ceramic backing material may be used to mechanically match the backing element to the piezoelectric source element, while minimizing the amplitude of reflections of the ultrasonic pulse generated by the piezoelectric element and reflected at the far end of the backing element. This ceramic backing material may provide consistent performance regardless of the surrounding pressure and temperature, making it particularly useful in borehole applications. ## Claims ### Claim 1 A system, comprising: an ultrasonic transducer for use in a borehole environment, comprising: a piezoelectric element; a pair of electrodes disposed one on each side of the piezoelectric element to enable a current flow through the piezoelectric element; and a backing element disposed on one side of the piezoelectric element to attenuate vibrations in the ultrasonic transducer from the piezoelectric element, wherein the backing element is a ceramic backing material, wherein the backing element is configured to eliminate acoustic reflections from the attenuated vibrations. ### Claim 2 (depends on 1) The system of claim 1, wherein the ceramic backing material has a mechanical Q factor of less than 10. ### Claim 3 (depends on 1) The system of claim 1, wherein the ultrasonic transducer further comprises a bonding material disposed between the ceramic backing material and the piezoelectric element to bond the ceramic backing material to the piezoelectric element, wherein the bonding material comprises an epoxy with ceramic powder or metal powder disposed therein. ### Claim 4 (depends on 1) The system of claim 1, wherein the backing element comprises a back end facing away from the piezoelectric element, wherein the back end is angled to reduce acoustic reflections through the backing element. ### Claim 5 (depends on 1) The system of claim 1, wherein the backing element comprises an angled back end facing away from the piezoelectric element to form a wedge-shaped ultrasonic transducer. ### Claim 6 (depends on 1) The system of claim 1, wherein the piezoelectric element is diced. ### Claim 7 (depends on 1) The system of claim 1, wherein the backing element is mechanically stable at temperatures up to 320° Celsius. ### Claim 8 A system, comprising: a borehole tool designed for use in a borehole, the borehole tool comprising at least one ultrasonic transducer, wherein the at least one ultrasonic transducer comprises: a piezoelectric element; a pair of electrodes disposed one on each side of the piezoelectric element to enable a current flow through the piezoelectric element; and a backing element disposed on one side of the piezoelectric element to attenuate vibrations in the ultrasonic transducer from the piezoelectric element, wherein the backing element is a ceramic backing material, wherein the backing element is configured to eliminate acoustic reflections from the attenuated vibrations. ### Claim 9 (depends on 8) The system of claim 8, wherein the borehole tool comprises a drill string comprising a plurality of ultrasonic transducers disposed circumferentially around the drill string to determine a distance from a drill cutter to a wall of the borehole, wherein each of the plurality of ultrasonic transducers comprise a backing element that is a ceramic backing material. ### Claim 10 (depends on 8) The system of claim 8, wherein the borehole tool comprises a wireline tool comprising the at least one ultrasonic transducer to measure corrosion of a casing disposed in the borehole, to detect a quality of a cement bond within the borehole, to map a shape of the borehole, or a combination thereof. ### Claim 11 (depends on 8) The system of claim 8, wherein the borehole tool comprises at least two ultrasonic transducers positioned to perform pitch-catch measurements within the borehole, wherein the at least two ultrasonic transducers each comprise a backing element that is a ceramic backing material. ### Claim 12 (depends on 8) The system of claim 8, wherein the backing element is machined to feature a sloping back end facing away from the piezoelectric element. ### Claim 13 A method, comprising: outputting an acoustic signal in a borehole environment via a piezoelectric element of an ultrasonic transducer; and attenuating vibration waves formed by the acoustic signal from the piezoelectric element, via a backing element disposed in the ultrasonic transducer, wherein the backing element is a ceramic backing material, wherein the backing element is configured to eliminate acoustic reflections from the attenuated vibration waves. ### Claim 14 (depends on 13) The method of claim 13, further comprising reducing reflections from the back end of the backing element via a machined surface of the backing element facing away from the piezoelectric element. ### Claim 15 (depends on 13) The method of claim 13, further comprising performing pitch-catch operations in the borehole environment via the ultrasonic transducer. ### Claim 16 (depends on 13) The method of claim 13, further comprising: supporting the ultrasonic transducer in the borehole environment via a drill string; and performing measurements of distance between a borehole wall and a drill cutter via the ultrasonic transducer. ### Claim 17 (depends on 13) The method of claim 13, further comprising: supporting the ultrasonic transducer in the borehole environment via a wireline; and performing measurements of casing corrosion, cement bond quality, borehole shape, or a combination thereof, via the ultrasonic transducer.