Abstract: Methods, systems, and devices for downhole evaluation using a sensor assembly that includes a sensor plate, wherein a surface of the sensor plate forms a portion of a surface of a downhole tool. Methods include bringing the surface of the sensor plate into contact with downhole fluid; generating a guided wave that propagates in the sensor plate by activating the sensor assembly at at least one frequency configured to excite both a symmetric mode and an anti-symmetric mode; making at least one first attenuation measurement of the symmetric mode of the guided wave; making at least one second attenuation measurement of the anti-symmetric mode of the guided wave; and using the at least one first attenuation measurement and the at least one second attenuation measurement to estimate at least one parameter of interest of the fluid. Methods may include submerging the surface of the sensor plate in a downhole fluid.

Abstract: Methods and apparatus for inspecting oilfield infrastructure components. Methods include estimating an optimal value for at least one excitation parameter for an acoustic excitation source to produce a guided wave of mixed multiple modes in the component; selecting at least one excitation parameter corresponding to an optimal simulated guided wave determined in dependence upon the application of waveform criteria to the time domain waveforms; and generating a guided wave in the tubular using the at least one optimal excitation parameter. Methods may include calculating a guided wave dispersion relation; modeling each of the plurality of simulated guided waves, wherein the modeling comprises generating a time domain waveform for each of a plurality of wave modes in dependence upon the acoustic excitation source; selecting the at least one excitation parameter corresponding to an optimal simulated guided wave determined in dependence upon the application of waveform criteria to the time domain waveforms.

Abstract: Methods and apparatuses for evaluating an earth formation intersected by a borehole. Methods include estimating a property of cement surrounding a tubular in the earth formation by: generating an acoustic signal with a logging tool in the borehole; estimating the property in dependence upon a late reflected wave field of a modified response acoustic signal, wherein the modified response acoustic signal is produced by suppression of a direct mode component.

Abstract: Methods, systems, devices, and products for well logging using a logging tool in a borehole in an earth formation. Methods include conveying the logging tool in the borehole on a carrier; taking acoustic well logging measurements with the logging tool including generating a multitone acoustic beam from at least one transmitter on the tool, the beam comprising a high frequency signal modulated by a low frequency envelope, the high frequency signal including a first subsignal at a first frequency and a second subsignal at a second frequency, and generating measurement information at at least one acoustic receiver on the logging tool in response to a plurality of acoustic reflections of the acoustic beam from at least one volume of interest in the formation; and estimating a property of the volume of interest using the measurement information.

Abstract: Systems, devices, and methods for estimating a value of a downhole parameter of interest. Aspects include an apparatus for evaluating a tubular. The apparatus may include a sensor including an electromagnetic acoustic transducer (EMAT) device configured to be conveyed into the tubular. The EMAT device may include measurement circuitry comprising at least one conductive coil; and a magnet array comprising magnets arranged with a corresponding direction of magnetization of each magnet oriented according to a configuration producing a greater magnetic flux on a first side of the array than on a second side opposing the first side. The magnetic flux produced from the second side may be substantially zero. In embodiments, the configuration of magnets comprises at least a first set of permanent magnets in a linear Halbach configuration.

Abstract: Methods, systems, and devices for downhole evaluation using a sensor assembly that includes a sensor plate, wherein a surface of the sensor plate forms a portion of a surface of a downhole tool. Methods include bringing the surface of the sensor plate into contact with downhole fluid; generating a guided wave that propagates in the sensor plate by activating the sensor assembly at at least one frequency configured to excite both a symmetric mode and an anti-symmetric mode; making at least one first attenuation measurement of the symmetric mode of the guided wave; making at least one second attenuation measurement of the anti-symmetric mode of the guided wave; and using the at least one first attenuation measurement and the at least one second attenuation measurement to estimate at least one parameter of interest of the fluid. Methods may include submerging the surface of the sensor plate in a downhole fluid.

Abstract: Systems, devices, and methods for evaluating a volume of interest of an earth formation. Methods include estimating a parameter of interest of a volume of the formation using a value of a signal property (frequency amplitude) for a second harmonic mode signal component of a detected acoustic signal from the volume. Methods may include activating a transmitter to propagate an acoustic wave through the volume; producing the detected acoustic signal at a receiver responsive to the acoustic wave; and identifying the fundamental mode signal and the second harmonic mode signal associated with the detected acoustic signal. Methods include estimating an acoustic wave non-linearity parameter (?) for the volume using a relationship between the value of the signal property of the second harmonic mode signal component and a value of the signal property for a fundamental mode signal component of the detected acoustic signal.

Abstract: Methods and apparatus for inspecting oilfield infrastructure components. Methods include estimating an optimal value for at least one excitation parameter for an acoustic excitation source to produce a guided wave of mixed multiple modes in the component; selecting at least one excitation parameter corresponding to an optimal simulated guided wave determined in dependence upon the application of waveform criteria to the time domain waveforms; and generating a guided wave in the tubular using the at least one optimal excitation parameter. Methods may include calculating a guided wave dispersion relation; modeling each of the plurality of simulated guided waves, wherein the modeling comprises generating a time domain waveform for each of a plurality of wave modes in dependence upon the acoustic excitation source; selecting the at least one excitation parameter corresponding to an optimal simulated guided wave determined in dependence upon the application of waveform criteria to the time domain waveforms.

Abstract: Methods, systems, devices, and products for well logging using a logging tool in a borehole in an earth formation. Methods include conveying the logging tool in the borehole on a carrier; taking acoustic well logging measurements with the logging tool including generating a multitone acoustic beam from at least one transmitter on the tool, the beam comprising a high frequency signal modulated by a low frequency envelope, the high frequency signal including a first subsignal at a first frequency and a second subsignal at a second frequency, and generating measurement information at at least one acoustic receiver on the logging tool in response to a plurality of acoustic reflections of the acoustic beam from at least one volume of interest in the formation; and estimating a property of the volume of interest using the measurement information.

Abstract: Systems, devices, and methods for estimating a value of a downhole parameter of interest. Aspects include an apparatus for evaluating a tubular. The apparatus may include a sensor including an electromagnetic acoustic transducer (EMAT) device configured to be conveyed into the tubular. The EMAT device may include measurement circuitry comprising at least one conductive coil; and a magnet array comprising magnets arranged with a corresponding direction of magnetization of each magnet oriented according to a configuration producing a greater magnetic flux on a first side of the array than on a second side opposing the first side. The magnetic flux produced from the second side may be substantially zero. In embodiments, the configuration of magnets comprises at least a first set of permanent magnets in a linear Halbach configuration.

Abstract: Systems, devices, and methods for evaluating a volume of interest of an earth formation. Methods include estimating a parameter of interest of a volume of the formation using a value of a signal property (frequency amplitude) for a second harmonic mode signal component of a detected acoustic signal from the volume. Methods may include activating a transmitter to propagate an acoustic wave through the volume; producing the detected acoustic signal at a receiver responsive to the acoustic wave; and identifying the fundamental mode signal and the second harmonic mode signal associated with the detected acoustic signal. Methods include estimating an acoustic wave non-linearity parameter (?) for the volume using a relationship between the value of the signal property of the second harmonic mode signal component and a value of the signal property for a fundamental mode signal component of the detected acoustic signal.