Piezo Sona-tool Corporation

Other

Essex Transducers Corporation

Undersea Transducer Technology, Inc.

Kkf Corporation

Kdc Corporation

Sona-tool Development Ltd.

Harry W Kompanek

James R Ligman

Eric D Plambeck

Peter Kaufman

Rickey H Ming

David K Carlson

A transducer member is made from a piezoelectric material (e.g. barium titanium) having a looped configuration and a gap in the loop and having properties of vibrating upon the introduction of an electrical voltage to the transducer member. A support member made from steel or aluminum and having a looped configuration and enveloping, and attached to, the transducer member has a gap aligned with the transducer member tap and has properties of vibrating with the transducer member. The transducer member may have a uniform thickness around its periphery or a progressively increasing thickness with progressive distances from the gap. The transducer has a high mechanical Q (e.g. 8-12) and a particular resonant frequency when disposed in air or in a vacuum. When the transducer is disposed below the earth's surface, its resonant frequency may vary because of variations in the earth's characteristics at the different positions. An alternating voltage having the particular frequency as its fundamental frequency is applied to the transducer member with a particular amplitude. The voltage has harmonics with large amplitudes (as in a squarewave) relative to the particular amplitude. When the transducer member is disposed in the earth, sound pressure waves are produced in the transducer with larger amplitudes at harmonics and overtones of the fundamental frequency over a wide frequency range than the magnitude of the amplitude at the fundamental frequency. The harmonics and overtures produce an enhanced recovery of the oil from the earth regardless of the earth's variable characteristics.

Transducer receiving voltage inputs, such as square waves, rich in harmonics

A transducer provides (a) increased magnitudes of vibrations without cracking and (b) increased power to the transducer, in response to alternating voltages, for producing transducer vibrations with increased magnitudes. A polycrystalline ceramic (e.g. polycrystalline lead titanate or polycrystalline lead zirconate) has a looped configuration with a gap and has properties of vibrating upon an introduction of an alternating voltage, preferably rich in harmonies, to the ceramic. The ceramic is cryogenically treated as by initially reducing its temperature to approximately &minus;100&deg; C., then disposing the ceramic in liquid nitrogen and thereafter gradually increasing its temperature to approximately room temperature. This increases the dielectric strength of the ceramic by prestressing the ceramic, thereby providing for the ceramic to receive increased voltages without cracking. An alternating voltage rich in harmonics (e.g. square wave voltage) may be applied to the ceramic. The transducer also includes a support member (e.g. steel or aluminum) having a looped configuration and having a gap aligned with the ceramic gap and having properties of vibrating with the ceramic. The support member envelopes, and is attached to, the ceramic. The support member may have a uniform thickness around its periphery or a progressively increasing thickness with progressive distances in opposite directions from the gap to enhance its ability to withstand cracking when subjected to vibrations. In other embodiments, a plurality of transducers may be combined in different ways to form a transducer assembly with enhanced power characteristics.

Transducers, and methods of producing transducers, with cryogenically treated transducer members

A support member preferably made of a metal such as cold rolled steel is disposed in a looped configuration and is provided with a gap. A transducer member preferably made of a piezoelectric material such as a ceramic is disposed within the support member. The transducer member is provided with a gap at a position corresponding to the gap in the support member. A closure member made from a suitable springlike material such as an alloy steel is attached to the opposite ends of the support member at the position of the gap as by welding. The closure member extends in a U-shaped configuration into the looped configuration (in section) defined by the support member and the ceramic member. The axial length of the closure member defines the bandwidth of the frequency vibrations generated by the transducer member. When the closure member extends from the gap into the looped configuration to a position near the end of the transducer member and the support member opposite the gap, a bracing member may be disposed between the closure member and the transducer member to brace the closure member. The opposite ends of the closure member are closed as by end caps.

Transducer assembly

First and second units have similar, preferably substantially identical, constructions. Each unit is preferably cylindrical and has an outer electrically conductive shell preferably made from a metal. A dielectric material, preferably a ceramic, abuts the inner surface of the electrically conductive shell in each unit. A conductive coating is disposed on the inner surface of the dielectric material in each unit. In this way, each unit defines a capacitor with the shell and the conductive coating constituting the capacitor plates. The shell and the dielectric material in each unit have axially extending openings of matching dispositions. The units are disposed in abutting relationship with the openings facing each other. An alternating voltage is applied between the conductive coating and the conductive shell in each unit. This causes current to flow through the capacitor in each unit and to produce vibrations of the shell and the dielectric material in each unit. Because of the bracing provided by the bonding of the two (2) units, the units are inhibited from breaking as a result of the vibrations. Furthermore, the units are able to respond to voltages of increased amplitude, thereby increasing the intensity of the vibrations. The bonding of the units also inhibits vibrations of the units in undesirable directions and concentrates the vibrations in a particular direction providing optimal benefits.

Transducer

A transducer assembly includes a hollow support member disposed in a looped configuration and having an axial opening. A hollow transducer supported within the support member may be made from a piezoelectric material and may be provided with an axial opening corresponding to position to the axial opening in the support member. In one embodiment, the outer surface of the support member may be thinned at spaced positions as by sockets or spaced axial grooves extending partially through the support member. The support member may be thinned at strategic positions to control the vibrational frequency and the frequency bandwidth of the transducer assembly. The thinned portions of the support member may receive a compliant material such as urethane to smoothen the outer surface of the support member. In another embodiment, the hollow interior of the transducer assembly may be filled with a compliant material, such as urethane, which may be provided with air chambers. The compliant material causes the shape of the transducer assembly to be retained, particularly when end caps are disposed on the support member, and causes the vibrations to be damped and the bandwidth of the vibrations to be increased. The air chambers produce a mismatch between the impedances inside and outside the transducer assembly and facilitate the transmission of substantially all of the vibrational energy outside of the assembly. In still other embodiments, members are included for bracing the support member and the transducer to increase the amplitudes of the assembly vibrations without damaging the transducer.

Transducer assemblies

A housing is constructed to define individual areas for depression to identify individual indicia such as numbers or the letters of the alphabet. A hard, electrically insulating material is attached to the housing to transmit strains produced in the housing by the depression of the individual areas on the housing. A plurality of thin sheets of an electrically insulating material are provided, each being attached to the insulating material at positions corresponding to the individual areas in the housing. A plurality of thin sheets of an electrically conductive material are also provided, each attached to an associated one of the thin sheets of insulating material. A plurality of ceramic crystals are also included, each attached to an individual one of the electrically conductive sheets. The electrically conductive sheets may be attached to the housing, which is preferably made from an electrically conductive material. This causes one surface of each ceramic crystal to be common to the adjacent area. Each crystal becomes stressed when the keyboard is depressed in the adjacent area on the keyboard. When the crystal becomes stressed, it causes an electrical signal to be generated on the ungrounded surface of the crystal.

Typewriter keyboard

A housing, preferably electrically conductive, defines individual areas for depression to identify individual indicia, e.g., number, alphabetical letters. A hard, electrically insulating material attached to the housing transmits strains produced by the depression of the individual areas on the housing. A plurality of thin electrically insulating sheets are attached to the hard insulating material at the individual areas in the housing. A plurality of thin electrically conductive sheets attached to the thin insulating sheets. The insulating sheets and the conductive sheets may constitute printed circuit segments. A plurality of ceramic crystals are attached to individual ones of the conductive sheets. The electrically conductive sheets are preferably coupled electrically to the housing. This causes one surface of each crystal to be common to the adjacent area. When the keyboard is depressed in the adjacent keyboard area, each crystal becomes stressed and causes an electrical signal to be generated on the ungrounded surface of the crystal.

Solid state keyboard

A casing in an oil well is constructed to provide for the flow of oil in the well. The casing cylindrical and may be perforated. The casing is resonant in a hoop mode at a particular fundamental frequency such as approximately 400 hertz. A transducer includes a transducer member disposed within a tubing in spaced relationship to the tubing. The transducer member may be a ceramic slotted at one end and supported by the tubing at the other end. A ring may envelope the ceramic member and may be slotted at the same position as the ceramic member. The tubing may be filled with a fluid which provides dielectric properties and operates to transmit vibrations from the transducer to the tubing. The transducer may vibrate in the hoop mode at the fundamental frequency of resonance of the casing. These vibrations are transmitted to the casing through the fluid in the tubing, the tubing and the oil in the casing to produce a resonance of the casing at the particular fundamental frequency in the hoop mode. Wet concrete is disposed around the casing. The transducer is then moved slowly upwardly, while vibrating the transducer, to eliminate any gas, oil or mud pockets in the concrete while the concrete is still wet. The upward movement of the transducer may be temporarily interrupted at positions where the gas, oil and mud pockets are known or suspected to exist.

Downhole transducer systems

An electroacoustical transducer includes a tubular member. The member has a gap extending the axial length of the member with a restricted circumferential length. The member has a particular thickness and/or diameter to vibrate at a particular frequency. A plurality of polarized sectionalized transducer elements are in closely stacked relationship within the member to provide unrestrained vibrations of the member at the ends defining the gap. The elements are bonded to the member to vibrate at the particular frequency in accordance with the introduction of alternating current signals to the elements. Means are operatively coupled to the transducer elements to introduce alternating current signals to the elements to produce vibrations of such elements. In one embodiment, the elements are disposed in an annular configuration in abutting relationship to one another and are bonded to the inner wall of the tubular member. In another embodiment, the elements are disposed in a linear configuration in abutting relationship to one another and are bonded to the inner wall of the tubular member at diametrical positions equally spaced from the gap. The elements are circumferentially polarized. An output member may be coupled to the tubular member at the position of the gap to vibrate with the tubular member. A plurality of transducers constructed as disclosed above may be disposed in stacked relationshp. The gaps in the tubular members of such transducers may be annularly displaced in phase to produce a particular directional pattern to the acoustic waves produced by such transducer array.

Electroacoustical transducer

A casing is disposed in an oil well and is constructed to provide for the flow of oil in the well. For example, the casing may be cylindrical and may be perforated in its cylindrical wall. The casing is resonant in a hoop mode at a particular fundamental frequency. This fundamental frequency may be in the order of approximately 400 hertz. A transducer includes a transducer member disposed within a tubing in spaced relationship to the tubing. The transducer member may be a ceramic slotted at one end and supported by the tubing at the other end. A ring may envelope the ceramic member and may be slotted at the same position as the ceramic member. The tubing may be filled with an oil which provides dielectric properties and operates to transmit vibrations from the transducer to the tubing. The transducer may vibrate in the hoop mode at the fundamental frequency of resonance of the casing. The transducer member is energized to obtain the production of vibrations in the transducer in the hoop mode. These vibrations are transmitted to the casing through the oil in the tubing, the tubing and the oil in the casing to produce a resonance of the casing at the particular fundamental frequency in the hoop mode.

Casing tuned downhole tool

Gravel is packed around a casing in an oil well to prevent sand from entering into the casing, to loosen the sand around the gravel and facilitate the flow of oil into the casing. The gravel is vibrated around the periphery of the casing at a particular harmonic between approximately 1100 Hertz and 1700 Hertz. The transducer may be slotted to facilitate the production of a considerable amount of energy at the particular harmonic without breaking the transducer. When slotted, the transducer may be disposed within a slotted ring to facilitate the production of a considerable amount of energy at the particular harmonic without breaking the transducer. The transducer and the slotted ring may be disposed within a sleeve which may be filled with oil. At least one of the anti-nodes of the transducer may be clamped to produce vibrations at the particular harmonic without producing vibrations at the fundamental frequency. The transducer may be tuned so that the frequency of the particular harmonic such as the fifth harmonic is at the lowest possible value. This may be accomplished by partially slotting the metal ring at a position displaced from the slot in the ring or by adding mass to the ends of the transducer. The module described above may be depended from the bottom of the casing in a plurality of similar modules whose slots may be annularly staggered to facilitate the packing of the gravel without voids.

Sonic gravel packing method and tool for downhole oil wells

An electromechanical transducer is made from a member providing for the introduction of electrical energy and the conversion of such energy to mechanical vibrations radially. First means cooperate with the transducer member in limiting the vibrations of the member in a direction for radially contracting the member. When the transducer member has a narrow gap extending along the length of the transducer member, the first means includes a resilient member having a width greater than the width of the gap and disposed in the gap to prestress the transducer member and prevent the ends of the gap from contacting each other during such vibrations. Second means cooperate with the transducer member for limiting the vibrations of the member in a direction for radially expanding the member. The second means include at least one band extending circumferentially around the transducer member for limiting the mechanical vibrations of the member in a direction for expanding the member. Means are provided for introducing electrical signals to the transducer member to produce the mechanical vibrations.

Prestressed, split cylindrical electromechanical transducer

A keyless system especially useful in controlling the doors and trunk of an automobile is disclosed. The overall system usually comprises an input station containing a keyboard, a signal processor, signal amplification means and an electromechanical grouping which converts the electrical output from the amplifier to mechanical movement in control of a lock. The system is activated by a touch control at the input keyboard and with the power section of the system energized, the lock is controlled in response to a proper sequence of digital input signals created by the operator. The input at the control station is described in terms of a keyboard having five selectors and resulting in approximately three thousand possible combinations for the base code. The signal processor responds to correct combinations of digital inputs with a drive signal. The signal processor is also programmable with temporary convenience codes which are loaded into the logic portion of the system with access preconditioned on entry of the base code.

Entry system

A sensor device having a vibratable surface which can be exposed to variousmaterials and used to determine the presence thereof is disclosed. The device includes a sandwich structure comprising a substrate coated with a piezoelectric material, a pickup electrode joined to the piezoelectric and a drive electrode also joined to the piezoelectric. The piezoelectric material is applied to the substrate as a slurry and when dried forms a ceramic coating which is chemically bonded to the substrate. The sensor is electrically driven to vibrate and depending upon the absence or presence of the material to be detected a characteristic vibrational frequency or amplitude of the sensing surface is observed to indicate contact with such material. Various embodiments are discussed including a rectangular configuration which is cantilevered from a support base and a circular configuration which is held circumferentially by the support base.

Growing community of inventors

Santa Barbara, CA, United States of America

Harry W Kompanek