Abstract: A fluid sensor device for measuring properties of a fluid is disclosed. The fluid sensor device includes a leaf cell sensor having a piezoelectric structure acting on a subdomain of the fluid that flows through the piezoelectric structure to create an intrinsic Helmholtz cavity response, and an enclosure enclosing the leaf cell sensor and including (i) a flowthrough shroud having an inlet that allows the fluid to enter the enclosure and pass across the leaf cell sensor, and a Helmholtz cavity wall that couples the intrinsic Helmholtz cavity response with an external acoustic field of the leaf sensor to increase a measurement sensitivity, (ii) a cylindrical housing having an outlet that allows the fluid to exit the enclosure, and (iii) a pressure feedthrough connector that transmits an electrical signal induced by the intrinsic Helmholtz cavity response to represent the properties of the fluid.

Abstract: Systems and a method for acoustic testing in a wellbore are provided. An exemplary acoustic source used in the acoustic testing includes an acoustic metamaterial generated from a geometrical inversion of a set of conformal contours developed from mapping of Tangent Circles, wherein the acoustic metamaterial is anistotropic with a horizontal axis (D_cell) smaller than a vertical axis (Rxy*D_cell).

Abstract: Borehole radar systems send a radar pulse into the subterranean formation using a transmitter. The radar pulse is reflected back when it encounters a formation feature that has a different electromagnetic property. The receiver receives the reflected energy back. However, in a highly conductive rock or in the presence of highly conductive fluids in the borehole region, the radar pulse is not transmitted far enough with sufficient intensity to be detected by the receivers. This technology provides a design for a device which amplifies the radar transmitted power, using a metamaterial. The metamaterial enhanced device is designed for an electric source frequency ranging between 1-5 GHz. Further, a metamaterial based antenna design achieves a directivity over D=20. This provides high intensity far field radiation into the subterranean formation which can be detected by the receivers with high signal to noise ratio (SNR).

Abstract: An apparatus for fluid measurement is disclosed. The apparatus includes a leaf cell sensor having one or more piezoelectric radial components connected to a circumferential component, a first electrode positioned on a distal face of at least one radial component, a second electrode positioned on a proximal face of the at least one radial component, a voltage source having a negative terminal and a positive terminal, the negative terminal being connected to the first electrode and the positive terminal being connected to the second electrode, an electric current measurement device connected to the first and second electrode to measure current flowing between the first and second electrode, and a processor of a computing device that determines, from the measured current, one or more properties of the fluid, where the voltage source couples electrical energy into the one or more piezoelectric radial components at multiple frequencies concurrently.

Abstract: A drill string vibration isolator includes a top connector configured to couple to a portion of a drill string; a bottom connector configured to couple to another portion of the drill string; a housing; and at least one elastic metamaterial configured to absorb mechanical energy vibrations generated through operation of a drilling rig to rotate the drill string and operation of an acoustic telemetry source to transmit downhole data to a terranean surface.

Abstract: A drill string vibration isolator includes a top connector configured to couple to a portion of a drill string; a bottom connector configured to couple to another portion of the drill string; a housing; and at least one elastic metamaterial configured to absorb mechanical energy vibrations generated through operation of a drilling rig to rotate the drill string and operation of an acoustic telemetry source to transmit downhole data to a terranean surface.

Abstract: A miniature Fourier transform mid-infrared (FT-MIR) spectrometer is provided. The FT-MIR includes a metasurface IR source to emit radiation when heated, a microelectromechanical (MEMS) interferometer, and a metasurface microbolometer to measure an interferogram from the MEMS interferometer, wherein the miniature FT-MIR spectrometer is less than about 20 mm in outer diameter.

Abstract: A microelectromechanical (MEMS) interferometer is provided. The MEMS interferometer includes a pair of movable mirrors that are positioned along perpendicular axes, wherein each of the pair of movable mirrors is coupled to a mechanism. The mechanism includes an electrostatic actuator driving a displacement amplification mechanism, and the displacement amplification mechanism driving each of the pair of the movable mirrors. The MEMS interferometer includes a beam splitter that is positioned at an intersection of the perpendicular axes extending through each movable mirror and the beam splitter. The MEMS interferometer also includes a metasurface microbolometer placed in line with the beam splitter to measure an intensity of a recombined beam from the pair of movable mirrors.

Abstract: A miniature Fourier transform mid-infrared (FT-MIR) spectrometer is provided. The FT-MIR includes a metasurface IR source to emit radiation when heated, a microelectromechanical (MEMS) interferometer, and a metasurface microbolometer to measure an interferogram from the MEMS interferometer, wherein the miniature FT-MIR spectrometer is less than about 20 mm in outer diameter.

Abstract: A microelectromechanical (MEMS) interferometer is provided. The MEMS interferometer includes a pair of movable mirrors that are positioned along perpendicular axes, wherein each of the pair of movable mirrors is coupled to a mechanism. The mechanism includes an electrostatic actuator driving a displacement amplification mechanism, and the displacement amplification mechanism driving each of the pair of the movable mirrors. The MEMS interferometer includes a beam splitter that is positioned at an intersection of the perpendicular axes extending through each movable mirror and the beam splitter. The MEMS interferometer also includes a metasurface microbolometer placed in line with the beam splitter to measure an intensity of a recombined beam from the pair of movable mirrors.

Abstract: A miniature Fourier transform mid-infrared (FT-MIR) spectrometer is provided. The FT-MIR includes a metasurface IR source to emit radiation when heated, a microelectromechanical (MEMS) interferometer, and a metasurface microbolometer to measure an interferogram from the MEMS interferometer, wherein the miniature FT-MIR spectrometer is less than about 20 mm in outer diameter.

Abstract: A miniature Fourier transform mid-infrared (FT-MIR) spectrometer is provided. The FT-MIR includes a metasurface IR source to emit radiation when heated, a microelectromechanical (MEMS) interferometer, and a metasurface microbolometer to measure an interferogram from the MEMS interferometer, wherein the miniature FT-MIR spectrometer is less than about 20 mm in outer diameter.

Abstract: This specification describes a leaf cell resonator sensor based on a geometry of Rhodonea conformal contours joined circumferentially in an eight-fold symmetry by central spoke electrode members. The resonator sensor may provide simultaneous and congruent measurement of fluid density and sound speed based on interaction of the leaf cell dynamics with self-formed Helmholtz cavity dilatational response of the fluid, and the associated changes in electrical admittance spectra in the sensor resulting from changes in fluid acoustic properties. A leaf cell resonator sensor may be capable of retrieving a density and sound speed measurement from fluid independent of the method of deployment, resulting from the principle of the self-formed Helmholtz resonant cavity feature that develops a standing acoustic wave pattern in the fluid without extraneous reflecting structure/hardware.

Abstract: Electromagnetic metamaterial cells are described. An example of an electromagnetic metamaterial cell includes spatially separate absorptive features disposed in a planar rotationally symmetric arrangement. Each of the absorptive features may include a curvilinear segment that is convex relative to a center of symmetry of the arrangement. In some embodiments, each of the absorptive features includes one or more forks extending from the curvilinear segment. Each of the one or more forks may include a stem and at least two tines extending from the stem. The electromagnetic metamaterial cell may be included in a detector, such as a microbolometer, which itself may be included in a Fourier-transform infrared spectroscopy (FTIR) system. In some embodiments, the FTIR system may be used to characterize fluid in a wellbore. The fluid may be a drilling fluid or a downhole fluid, such as crude oil.

Abstract: Systems and methods for vibration attenuation, and for investigating a subsurface volume of interest from a borehole. System embodiments may include a vibration attenuation system, comprising: at least one vibration attenuator configured to dynamically isolate a vibration source, the at least one vibration attenuator comprising metamaterial defining a plurality of cells; wherein at least one cell of the plurality of cells comprises a plurality of sub-cells azimuthally arrayed about an axis of alignment, and at least one sub-cell of the plurality is defined by a solid, the at least one sub-cell including a plurality of cell segments substantially oriented in alignment with a mapping geometry comprising an inversion of a canonical tangent circles mapping. The vibration source may comprise an acoustic source. The system may have an enclosure having the acoustic source and the at least one receiver disposed therein, with the at least one acoustic attenuator is positioned between.

Abstract: Systems and methods for vibration attenuation, and for investigating a subsurface volume of interest from a borehole. System embodiments may include a vibration attenuation system, comprising: at least one vibration attenuator configured to dynamically isolate a vibration source, the at least one vibration attenuator comprising metamaterial defining a plurality of cells; wherein at least one cell of the plurality of cells comprises a plurality of sub-cells azimuthally arrayed about an axis of alignment, and at least one sub-cell of the plurality is defined by a solid, the at least one sub-cell including a plurality of cell segments substantially oriented in alignment with a mapping geometry comprising an inversion of a canonical tangent circles mapping. The vibration source may comprise an acoustic source. The system may have an enclosure having the acoustic source and the at least one receiver disposed therein, with the at least one acoustic attenuator is positioned between.

Abstract: Electromagnetic metamaterial cells are described. An example of an electromagnetic metamaterial cell includes spatially separate absorptive features disposed in a planar rotationally symmetric arrangement. Each of the absorptive features may include a curvilinear segment that is convex relative to a center of symmetry of the arrangement. In some embodiments, each of the absorptive features includes one or more forks extending from the curvilinear segment. Each of the one or more forks may include a stem and at least two tines extending from the stem. The electromagnetic metamaterial cell may be included in a detector, such as a microbolometer, which itself may be included in a Fourier-transform infrared spectroscopy (FTIR) system. In some embodiments, the FTIR system may be used to characterize fluid in a wellbore. The fluid may be a drilling fluid or a downhole fluid, such as crude oil.

Abstract: This specification describes a leaf cell resonator sensor based on a geometry of Rhodonea conformal contours joined circumferentially in an eight-fold symmetry by central spoke electrode members. The resonator sensor may provide simultaneous and congruent measurement of fluid density and sound speed based on interaction of the leaf cell dynamics with self-formed Helmholtz cavity dilatational response of the fluid, and the associated changes in electrical admittance spectra in the sensor resulting from changes in fluid acoustic properties. A leaf cell resonator sensor may be capable of retrieving a density and sound speed measurement from fluid independent of the method of deployment, resulting from the principle of the self-formed Helmholtz resonant cavity feature that develops a standing acoustic wave pattern in the fluid without extraneous reflecting structure/hardware.

Abstract: A system and method of estimating properties of a wellbore fluid that directs the fluid through a cavity, and generates acoustic waves in the fluid while in the cavity. The acoustic waves are generated by oscillating an electroactive material over a range of frequencies. An electrical admittance spectra of the electroactive material is measured over the range of frequencies; where the electrical admittance spectra includes the magnitude, real, and imaginary components. Differences between the maximum values for each component and a vacuum electrical spectra are calculated, the differences are substituted into estimator equations to estimate the fluid properties. Electrical admittance spectra of the electroactive material was simulated for a series of known fluids flowing through the cavity, and a multi-regression statistical analysis was then used to derive the estimator equations.

Abstract: Apparatus, systems, and methods for investigating a subsurface volume of interest from a borehole. Apparatus comprise an enclosure configured for conveyance along the borehole; an acoustic source in the enclosure configured to generate acoustic signals; a lens assembly disposed in the enclosure and next to the acoustic source, the lens assembly being formed of a plurality of lens elements; wherein each lens element comprises a plurality of cells arranged in a curvilinear cell array, each cell formed as a column oriented transverse to a direction of travel of the acoustical signals. The plurality of cells may be arranged according to a conformal mapping geometry, including a canonical Bipolar conformal mapping transformation of constant [u,v] contour lines to [x,y] Cartesian coordinates. A portion of the cells are scaled down in size by a scale factor. The scale factor corresponding to each cell of the portion varies non-monotonically along periodicity lines.