# US 8,570,832 B2 · Variable throat venturi flow meter having a plurality of section-varying elements > Agents: this data is available as JSON from the patentgrep API and MCP server — see https://patentgrep.com/llms.txt - Number: US 8,570,832 B2 - Document ID: US8570832B2 - Status: Granted - Kind: B2 - Application number: 12/644,049 - Filed: 2009-12-22 - Published: 2010-07-01 - Granted: 2013-10-29 - Earliest claimed: 2008-12-31 - Assignees: Schlumberger Technology Corporation - Applicants: Christophe Rayssiguier; Laurent Alteirac - Inventors: Christophe Rayssiguier; Laurent Alteirac - Web page: https://patentgrep.com/patent/US8570832B2 ## CPC - G01V 1/16: Receiving elements for seismic signals; Arrangements or adaptations of receiving elements - E21B 47/16: through the drill string or casing {, e.g. by torsional acoustic waves} - G01V: GEOPHYSICS; GRAVITATIONAL MEASUREMENTS; DETECTING MASSES OR OBJECTS; TAGS (means for indicating the location of accidentally buried, e.g. snow-buried, persons A63B29/02) - E21B: EARTH OR ROCK DRILLING; OBTAINING OIL, GAS, WATER, SOLUBLE OR MELTABLE MATERIALS OR A SLURRY OF MINERALS FROM WELLS ## Abstract An acoustic transceiver assembly including a housing, an oscillator, and a blocking element. The housing has at least one inner wall defining a cavity. The cavity has a first end and a second end defining an axis of said acoustic transceiver assembly. The oscillator is provided in said cavity. The oscillator is provided with a transducer element, and a backing mass positioned adjacent to the transducer element. A blocking element is positioned inside the cavity and adjacent to the oscillator. The blocking element is adapted to restrain a portion of said backing mass at a first pressure to thereby restrain the backing mass from lateral movement relative to the axis of the acoustic transceiver assembly. The blocking element is also adapted to release the backing mass at a second pressure. ## Claims ### Claim 1 An acoustic transceiver assembly comprising: a housing having at least one inner wall defining a cavity, the cavity having a first end and a second end defining an axis of the acoustic transceiver assembly; an oscillator provided in the cavity, the oscillator comprising: a transducer element positioned at the first end of the cavity, a backing mass positioned adjacent the transducer element, wherein the transducer element is disposed between the backing mass and the first end of the cavity; a blocking element positioned adjacent the oscillator in the cavity, the blocking element being adapted to restrain a portion of the backing mass from lateral movement relative to the axis of the acoustic transceiver assembly, and to permit oscillations of the backing mass, wherein the blocking element restrains the backing mass at a first pressure and releases the backing mass at a second pressure to permit oscillations of the backing mass; at least one blocking spring biased against the blocking element; and an equalizing chamber having a port hole open to receiving the first pressure and/or the second pressure. ### Claim 2 (depends on 1) The acoustic transceiver assembly of claim 1, further comprising at least one seal for sealing off the equalizing chamber. ### Claim 3 (depends on 1) The acoustic transceiver assembly of claim 1, wherein the second pressure is higher than the first pressure. ### Claim 4 (depends on 1) The acoustic transceiver assembly of claim 1, wherein the first pressure is atmospheric pressure, and the second pressure is hydrostatic pressure. ### Claim 5 (depends on 1) The acoustic transceiver assembly of claim 1, wherein the blocking element is conical. ### Claim 6 An acoustic transceiver assembly comprising: a housing having at least one inner wall defining a cavity, the cavity having a first end and a second end defining an axis of the acoustic transceiver assembly; an oscillator provided in the cavity, the oscillator comprising: a transducer element positioned at the first end of the cavity, a backing mass positioned adjacent the transducer element, wherein the transducer element is disposed between the backing mass and the first end of the cavity; a blocking element positioned adjacent the oscillator in the cavity, the blocking element being adapted to restrain a portion of the backing mass from lateral movement relative to the axis of the acoustic transceiver assembly, and to permit oscillations of the backing mass; and at least one preloading spring having a first end coupled to the backing mass and a second end coupled to the first end of the cavity. ### Claim 7 A downhole tool comprising: a sensor for monitoring a downhole parameter; and an acoustic transceiver assembly in communication with the sensor, the acoustic transceiver assembly comprising: a housing having at least one inner wall defining a cavity, the cavity having a first end and a second end defining an axis of the acoustic transceiver assembly; an oscillator provided in the cavity, the oscillator comprising: a transducer element positioned at the first end of the cavity, a backing mass positioned adjacent the transducer element, and wherein the transducer element is disposed between the backing mass and the first end of the cavity; and a blocking element positioned adjacent the oscillator in the cavity, the blocking element being adapted to restrain a portion of the backing mass from lateral movement relative to the axis of the acoustic transceiver assembly, and to permit oscillations of the backing mass, wherein the blocking element restrains the backing mass at a first pressure and releases the backing mass at a second pressure to permit oscillations of the backing mass; at least one blocking spring biased against the blocking element; and an equalizing chamber having a port hole open to receiving the first pressure and/or the second pressure. ### Claim 8 (depends on 7) The downhole tool of claim 7, wherein the acoustic transceiver assembly further comprises at least one seal for sealing off the equalizing chamber. ### Claim 9 (depends on 7) The downhole tool of claim 7, wherein the second pressure is higher than the first pressure. ### Claim 10 (depends on 7) The downhole tool of claim 7, wherein the first pressure is atmospheric pressure, and the second pressure is hydrostatic pressure. ### Claim 11 (depends on 7) The downhole tool of claim 7, wherein the blocking element of the acoustic transceiver assembly is conical. ### Claim 12 A downhole tool comprising: a sensor for monitoring a downhole parameter; and an acoustic transceiver assembly in communication with the sensor, the acoustic transceiver assembly comprising: a housing having at least one inner wall defining a cavity, the cavity having a first end and a second end defining an axis of the acoustic transceiver assembly; an oscillator provided in the cavity, the oscillator comprising: a transducer element positioned at the first end of the cavity, a backing mass positioned adjacent the transducer element, wherein the transducer element is disposed between the backing mass and the first end of the cavity; a blocking element positioned adjacent the oscillator in the cavity, the blocking element being adapted to restrain a portion of the backing mass from lateral movement relative to the axis of the acoustic transceiver assembly, and to permit oscillations of the backing mass; and at least one preloading spring having a first end coupled to the backing mass and a second end coupled to the first end of the cavity. ### Claim 13 An acoustic transceiver assembly comprising: a housing having at least one inner wall defining a cavity, the cavity having a first end and a second end defining an axis of the acoustic transceiver assembly; an oscillator provided in the cavity, the oscillator comprising: a piezoelectric element positioned at the first end of the cavity, a backing mass positioned adjacent the piezoelectric element, and wherein the piezoelectric element is disposed between the backing mass and the first end of the cavity; a blocking element positioned adjacent the oscillator in the cavity, the blocking element being adapted to restrain a portion of the backing mass from lateral movement relative to the axis of the acoustic transceiver assembly, and to permit oscillations of the backing mass, wherein the blocking element restrains the backing mass at a first pressure and releases the backing mass at a second pressure to permit oscillations of the backing mass at least one blocking spring biased against the blocking element; and an equalizing chamber having a port hole open to receiving the first pressure and/or the second pressure. ### Claim 14 (depends on 13) The acoustic transceiver assembly of claim 13, further comprising at least one seal for sealing off the equalizing chamber. ### Claim 15 (depends on 13) The acoustic transceiver assembly of claim 13, wherein the second pressure is higher than the first pressure. ### Claim 16 (depends on 13) The acoustic transceiver assembly of claim 13, wherein the first pressure is atmospheric pressure, and the second pressure is hydrostatic pressure. ### Claim 17 (depends on 13) The acoustic transceiver assembly of claim 13, wherein the blocking element is conical. ### Claim 18 An acoustic transceiver assembly comprising: a housing having at least one inner wall defining a cavity, the cavity having a first end and a second end defining an axis of the acoustic transceiver assembly; an oscillator provided in the cavity, the oscillator comprising: a piezoelectric element positioned at the first end of the cavity, a backing mass positioned adjacent the piezoelectric element, and wherein the piezoelectric element is disposed between the backing mass and the first end of the cavity; a blocking element positioned adjacent the oscillator in the cavity, the blocking element being adapted to restrain a portion of the backing mass from lateral movement relative to the axis of the acoustic transceiver assembly, and to permit oscillations of the backing mass; and at least one preloading spring having a first end coupled to the backing mass and a second end coupled to the first end of the cavity. ### Claim 19 A method for making an acoustic transceiver assembly for introducing acoustic signals into an elastic media positioned in a well bore, comprising the steps of: forming an oscillator by acoustically coupling a backing mass to a transducer element; suspending the oscillator in a housing with a blocking element positioned adjacent to the backing mass, wherein the blocking element restrains the backing mass at a first pressure and releases the backing mass at a second pressure; forming an equalizing chamber between the blocking element and the housing; and forming at least one port hole in the equalizing chamber and through the housing, wherein the at least one port hole is adapted to receive the first and/or second pressures. ### Claim 20 (depends on 19) The method of claim 19 further including the step of forming at least one seal for sealing off the equalizing chamber. ### Claim 21 (depends on 19) The method of claim 19 wherein the blocking element is conical.