Patents by Inventor Barbara C. Gilstad
Barbara C. Gilstad has filed for patents to protect the following inventions. This listing includes patent applications that are pending as well as patents that have already been granted by the United States Patent and Trademark Office (USPTO).
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Publication number: 20180042627Abstract: Adaptive lithotripsy systems assist diagnosis and treatment of patients with kidney stones (stones being associated with subsequent development of cancer). As stimulation vibration is transmitted to the patient, both its total transmitted power and power spectral density (PSD) are tailored to individual patient needs. One such need is for progressive stone fragmentation (a hallmark of adaptive lithotripsy systems) at minimum power levels. And minimum power levels are achieved through two adaptive mechanisms for shifting PSD to concentrate transmitted vibration power in more effective frequency ranges. This concentration necessarily reduces power in relatively ineffective ranges, thus minimizing collateral tissue damage. Effective ranges for vibration power concentration are estimated in near-real time using backscatter vibration that is retransmitted from resonating stones while encoding information on the stones' existence, size and composition.Type: ApplicationFiled: July 10, 2017Publication date: February 15, 2018Inventors: Dennis W. Gilstad, Barbara C. Gilstad
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Patent number: 9879507Abstract: Adaptive stimulation systems combine impulse-generated swept-frequency stimulation vibration with cyclically-varying hydraulic pressure to provide adaptive down-hole stimulation. Swept-frequency stimulation vibration arises from cyclical shifts of the power spectral density (PSD) of each stimulator's fluid interface vibration (via closed-loop control of the rebound cycle time and/or the fluid interface's effective elastic modulus). PSD's are adjusted for resonance excitation and fracturing of geologic materials at varying distances from a wellbore, closed-loop control incorporating backscatter vibration from stimulated geologic material. One or more stimulators generate vibration in bursts comprising a plurality of vibration frequencies. Timed signals from a programmable controller affect directional propagation of combined vibration wave fronts from a stimulator array. As fracturing proceeds to smaller (e.g.Type: GrantFiled: August 25, 2017Date of Patent: January 30, 2018Inventors: Dennis W. Gilstad, Barbara C. Gilstad
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Publication number: 20180003009Abstract: Adaptive stimulation systems combine impulse-generated swept-frequency stimulation vibration with cyclically-varying hydraulic pressure to provide adaptive down-hole stimulation. Swept-frequency stimulation vibration arises from cyclical shifts of the power spectral density (PSD) of each stimulator's fluid interface vibration (via closed-loop control of the rebound cycle time and/or the fluid interface's effective elastic modulus). PSD's are adjusted for resonance excitation and fracturing of geologic materials at varying distances from a wellbore, closed-loop control incorporating backscatter vibration from stimulated geologic material. One or more stimulators generate vibration in bursts comprising a plurality of vibration frequencies. Timed signals from a programmable controller affect directional propagation of combined vibration wave fronts from a stimulator array. As fracturing proceeds to smaller (e.g.Type: ApplicationFiled: August 25, 2017Publication date: January 4, 2018Inventors: Dennis W. Gilstad, Barbara C. Gilstad
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Patent number: 9777556Abstract: Adaptive stimulation systems combine impulse-generated swept-frequency stimulation vibration with cyclically-varying hydraulic pressure to provide adaptive down-hole stimulation. Swept-frequency stimulation vibration arises from cyclical shifts of the power spectral density (PSD) of each stimulator's vibration (via closed-loop control of rebound cycle time). PSD's are adjusted for resonance excitation, fracturing and/or analysis of geologic materials at varying distances from a wellbore. And closed-loop control incorporates backscatter vibration from stimulated geologic material. Stimulators can be arranged singly or in spatial arrays of multiple stimulators, each stimulator generating vibration in bursts comprising a plurality of vibration frequencies. Timed signals from a programmable controller affect directional propagation of combined vibration wave fronts from a stimulator array. As fracturing proceeds to smaller (e.g.Type: GrantFiled: October 22, 2015Date of Patent: October 3, 2017Inventors: Dennis W. Gilstad, Barbara C. Gilstad
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Publication number: 20170114620Abstract: Adaptive stimulation systems combine impulse-generated swept-frequency stimulation vibration with cyclically-varying hydraulic pressure to provide adaptive down-hole stimulation. Swept-frequency stimulation vibration arises from cyclical shifts of the power spectral density (PSD) of each stimulator's vibration (via closed-loop control of rebound cycle time). PSD's are adjusted for resonance excitation, fracturing and/or analysis of geologic materials at varying distances from a wellbore. And closed-loop control incorporates backscatter vibration from stimulated geologic material. Stimulators can be arranged singly or in spatial arrays of multiple stimulators, each stimulator generating vibration in bursts comprising a plurality of vibration frequencies. Timed signals from a programmable controller affect directional propagation of combined vibration wave fronts from a stimulator array. As fracturing proceeds to smaller (e.g.Type: ApplicationFiled: October 22, 2015Publication date: April 27, 2017Inventors: Dennis W. Gilstad, Barbara C. Gilstad
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Patent number: 9169707Abstract: Tunable down-hole stimulation arrays feature closed-loop control of spatial arrays comprising several connected stimulators. Each stimulator is responsive to a timed activation signal. Stimulators periodically transmit bursts comprising a plurality of vibration frequencies, each burst having an adjustable power spectral density (PSD) that is tunable via an adjustable rebound cycle time. Rebound cycle times also affect vibration interference among array stimulators, while simultaneous or sequential timed activation signals from a programmable controller affect directional propagation of combined vibration wave fronts from an array. Stimulator PSD's are adjusted for resonance excitation and fracturing of adjacent geologic materials. Closed-loop feedback control incorporates backscatter vibration from stimulated geologic material. As fracturing proceeds to smaller (proppant-sized) fragments having higher resonant frequencies, PSD's are up-shifted, increasing relative power in higher vibration frequencies.Type: GrantFiled: January 22, 2015Date of Patent: October 27, 2015Inventors: Dennis W. Gilstad, Barbara C. Gilstad
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Patent number: 9080690Abstract: Tunable check valves reduce valve-generated vibration to increase the reliability of tunable fluid ends. Selected improved designs described herein reflect disparate applications of identical technical principles (relating to, e.g., the vibration spectrum of an impulse). Tunable check valve embodiments comprise a family including, but not limited to, tunable check valve assemblies, tunable valve seats, and tunable radial arrays. Each such tunable embodiment, in turn, contributes to blocking excitation of fluid end resonances, thus reducing the likelihood of fluid end failures associated with fatigue cracking and/or corrosion fatigue. By down-shifting the frequency domain of each valve-closing impulse shock, initial excitation of fluid end resonances is minimized.Type: GrantFiled: October 27, 2014Date of Patent: July 14, 2015Inventors: Dennis W. Gilstad, Barbara C. Gilstad
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Patent number: 9027636Abstract: Tunable down-hole stimulation systems feature closed-loop control of pumps and tunable down-hole stimulators. Stimulators generate and hydraulically transmit broad vibration spectra tuned for resonance excitation and fracturing of geologic materials adjacent to the wellbore. Feedback data for controlling stimulation includes backscatter vibration originating in stimulated geologic material and detected at the stimulator(s). For initial fracturing with relatively large particle sizes, the power spectral density (PSD) of each stimulator output is down-shifted toward the lower resonant frequencies of large particles. As fracturing proceeds to smaller (proppant-sized) fragments having higher resonant frequencies, backscatter vibration guides progressive up-shifting of stimulator PSD to higher vibration frequencies. Stimulator power requirements are minimized by concentrating vibration energy efficiently in frequency bands to which geologic materials are most sensitive at every stage of stimulation.Type: GrantFiled: July 25, 2014Date of Patent: May 12, 2015Inventors: Dennis W. Gilstad, Barbara C. Gilstad
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Publication number: 20150040998Abstract: Tunable check valves reduce valve-generated vibration to increase the reliability of tunable fluid ends. Selected improved designs described herein reflect disparate applications of identical technical principles (relating to, e.g., the vibration spectrum of an impulse). Tunable check valve embodiments comprise a family including, but not limited to, tunable check valve assemblies, tunable valve seats, and tunable radial arrays. Each such tunable embodiment, in turn, contributes to blocking excitation of fluid end resonances, thus reducing the likelihood of fluid end failures associated with fatigue cracking and/or corrosion fatigue. By down-shifting the frequency domain of each valve-closing impulse shock, initial excitation of fluid end resonances is minimized.Type: ApplicationFiled: October 27, 2014Publication date: February 12, 2015Inventors: Dennis W. Gilstad, Barbara C. Gilstad
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Patent number: 8944409Abstract: Tunable fluid ends reduce valve-generated vibration to increase fluid-end reliability. Tunable fluid end embodiments comprise a family, each family member comprising a fluid end housing with at least one installed tunable component chosen from: tunable check valve assemblies, tunable valve seats, tunable radial arrays and/or tunable plunger seals. Each tunable component, in turn, contributes to blocking excitation of fluid end resonances, thus reducing the likelihood of fluid end failures associated with fatigue cracking and/or corrosion fatigue. By down-shifting the frequency domain of each valve-closing impulse shock, initial excitation of fluid end resonances is minimized. Subsequent damping and/or selective attenuation of vibration likely to excite one or more predetermined (and frequently localized) fluid end resonances represents further optimal use of fluid end vibration-control resources.Type: GrantFiled: January 30, 2014Date of Patent: February 3, 2015Inventors: Dennis W. Gilstad, Barbara C. Gilstad
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Patent number: 8939200Abstract: Selected designs for reciprocating pumps and down-hole well-stimulation equipment reflect disparate applications of identical technical principles (relating to, e.g., the vibration spectrum of an impulse). In certain of these designs, the vibration spectrum is controlled, suppressed and/or damped using tunable components to limit destructive excitation of resonances; in others the vibration spectrum is tuned at its source for maximum resonance excitation. For example, tunable fluid ends control valve-generated vibration to increase fluid-end reliability. By down-shifting the frequency domain of each valve-closing impulse shock, initial excitation of fluid end resonances is minimized. Subsequent damping and/or selective attenuation of vibration likely to excite one or more predetermined (and frequently localized) fluid end resonances represents further optimal use of fluid end vibration-control resources.Type: GrantFiled: April 9, 2014Date of Patent: January 27, 2015Inventors: Dennis W. Gilstad, Barbara C. Gilstad
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Patent number: 8905376Abstract: Tunable check valves reduce valve-generated vibration to increase the reliability of tunable fluid ends. Selected improved designs described herein reflect disparate applications of identical technical principles (relating to, e.g., the vibration spectrum of an impulse). Tunable check valve embodiments comprise a family including, but not limited to, tunable check valve assemblies, tunable valve seats, and tunable radial arrays. Each such tunable embodiment, in turn, contributes to blocking excitation of fluid end resonances, thus reducing the likelihood of fluid end failures associated with fatigue cracking and/or corrosion fatigue. By down-shifting the frequency domain of each valve-closing impulse shock, initial excitation of fluid end resonances is minimized.Type: GrantFiled: April 25, 2014Date of Patent: December 9, 2014Inventors: Dennis W. Gilstad, Barbara C. Gilstad
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Publication number: 20140332199Abstract: Tunable down-hole stimulation systems feature closed-loop control of pumps and tunable down-hole stimulators. Stimulators generate and hydraulically transmit broad vibration spectra tuned for resonance excitation and fracturing of geologic materials adjacent to the wellbore. Feedback data for controlling stimulation includes backscatter vibration originating in stimulated geologic material and detected at the stimulator(s). For initial fracturing with relatively large particle sizes, the power spectral density (PSD) of each stimulator output is down-shifted toward the lower resonant frequencies of large particles. As fracturing proceeds to smaller (proppant-sized) fragments having higher resonant frequencies, backscatter vibration guides progressive up-shifting of stimulator PSD to higher vibration frequencies. Stimulator power requirements are minimized by concentrating vibration energy efficiently in frequency bands to which geologic materials are most sensitive at every stage of stimulation.Type: ApplicationFiled: July 25, 2014Publication date: November 13, 2014Inventors: Dennis W. Gilstad, Barbara C. Gilstad
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Patent number: 8827244Abstract: Tunable fluid ends reduce valve-generated vibration to increase fluid-end reliability. Tunable fluid end embodiments comprise a family, each family member comprising a fluid-end housing with at least one installed tunable component chosen from: tunable check valve assemblies, tunable valve seats, tunable radial arrays and/or tunable plunger seals. Each tunable component, in turn, contributes to blocking excitation of fluid end resonances, thus reducing the likelihood of fluid end failures associated with fatigue cracking and/or corrosion fatigue. By down-shifting the frequency domain of each valve-closing impulse shock, initial excitation of fluid end resonances is minimized. Subsequent damping and/or selective attenuation of vibration likely to excite one or more predetermined (and frequently localized) fluid end resonances represents further optimal use of fluid end vibration-control resources.Type: GrantFiled: January 30, 2014Date of Patent: September 9, 2014Inventors: Dennis W. Gilstad, Barbara C. Gilstad
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Publication number: 20140230928Abstract: Tunable check valves reduce valve-generated vibration to increase the reliability of tunable fluid ends. Selected improved designs described herein reflect disparate applications of identical technical principles (relating to, e.g., the vibration spectrum of an impulse). Tunable check valve embodiments comprise a family including, but not limited to, tunable check valve assemblies, tunable valve seats, and tunable radial arrays. Each such tunable embodiment, in turn, contributes to blocking excitation of fluid end resonances, thus reducing the likelihood of fluid end failures associated with fatigue cracking and/or corrosion fatigue. By down-shifting the frequency domain of each valve-closing impulse shock, initial excitation of fluid end resonances is minimized.Type: ApplicationFiled: April 25, 2014Publication date: August 21, 2014Inventors: Dennis W. Gilstad, Barbara C. Gilstad
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Patent number: 8746654Abstract: Tunable fluid end embodiments comprise a family, each family member comprising a pump housing with at least one installed tunable component chosen from: tunable valve assemblies, tunable valve seats, tunable radial arrays and/or tunable plunger seals. For example, a tunable valve assembly or tunable radial array selectively attenuates valve-generated vibration at its source, thus reducing the likelihood of fluid end failures associated with fatigue cracking and/or corrosion fatigue. Adding tunable valve seats and/or tunable plunger seals to a fluid end facilitates optimal damping and/or selective attenuation of vibration at one or more predetermined (and frequently localized) fluid end resonant frequencies. Thus, the likelihood of exciting destructive resonances in a pump's fluid end housing is further reduced.Type: GrantFiled: October 7, 2013Date of Patent: June 10, 2014Inventors: Dennis W. Gilstad, Barbara C. Gilstad
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Publication number: 20140144527Abstract: Tunable fluid ends reduce valve-generated vibration to increase fluid-end reliability. Tunable fluid end embodiments comprise a family, each family member comprising a fluid-end housing with at least one installed tunable component chosen from: tunable check valve assemblies, tunable valve seats, tunable radial arrays and/or tunable plunger seals. Each tunable component, in turn, contributes to blocking excitation of fluid end resonances, thus reducing the likelihood of fluid end failures associated with fatigue cracking and/or corrosion fatigue. By down-shifting the frequency domain of each valve-closing impulse shock, initial excitation of fluid end resonances is minimized. Subsequent damping and/or selective attenuation of vibration likely to excite one or more predetermined (and frequently localized) fluid end resonances represents further optimal use of fluid end vibration-control resources.Type: ApplicationFiled: January 30, 2014Publication date: May 29, 2014Inventors: Dennis W. Gilstad, Barbara C. Gilstad
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Publication number: 20140144528Abstract: Tunable fluid ends reduce valve-generated vibration to increase fluid-end reliability. Tunable fluid end embodiments comprise a family, each family member comprising a fluid end housing with at least one installed tunable component chosen from: tunable check valve assemblies, tunable valve seats, tunable radial arrays and/or tunable plunger seals. Each tunable component, in turn, contributes to blocking excitation of fluid end resonances, thus reducing the likelihood of fluid end failures associated with fatigue cracking and/or corrosion fatigue. By down-shifting the frequency domain of each valve-closing impulse shock, initial excitation of fluid end resonances is minimized. Subsequent damping and/or selective attenuation of vibration likely to excite one or more predetermined (and frequently localized) fluid end resonances represents further optimal use of fluid end vibration-control resources.Type: ApplicationFiled: January 30, 2014Publication date: May 29, 2014Inventors: Dennis W. Gilstad, Barbara C. Gilstad
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Patent number: 8720857Abstract: Tunable fluid end embodiments comprise a family, each family member comprising a pump housing with at least one installed tunable component chosen from: tunable valve assemblies, tunable valve seats, tunable radial arrays and/or tunable plunger seals. For example, a tunable valve assembly or tunable radial array selectively attenuates valve-generated vibration at its source, thus reducing the likelihood of fluid end failures associated with fatigue cracking and/or corrosion fatigue. Adding tunable valve seats and/or tunable plunger seals to a fluid end facilitates optimal damping and/or selective attenuation of vibration at one or more predetermined (and frequently localized) fluid end resonant frequencies. Thus, the likelihood of exciting destructive resonances in a pump's fluid end housing is further reduced.Type: GrantFiled: October 7, 2013Date of Patent: May 13, 2014Inventors: Dennis W. Gilstad, Barbara C. Gilstad
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Patent number: 8708306Abstract: A tunable valve assembly reduces valve-generated vibration. One embodiment comprises a valve body and valve seat having substantially collinear longitudinal axes. A rebound characteristic frequency is associated with rebound of the elastic valve body base plate from forceful contact with the valve seat. A central cavity in the valve body encloses a spring-mass damper optionally immersed in a dilatant liquid and having a damper resonant frequency approximating a pump housing resonance. A lateral support assembly adjustably secured to the valve seat has a support resonant frequency designed in conjunction with the rebound characteristic frequency and the damper resonant frequency. Combined hysteresis heat loss associated with the above three vibration frequencies is reflected in lower closing energy impulse amplitude and damping of associated vibrations.Type: GrantFiled: September 27, 2013Date of Patent: April 29, 2014Inventors: Barbara C. Gilstad, Dennis W. Gilstad