Abstract: Systems, methods, and software for determining a thickness of a well casing are described. In some aspects, the thickness of the well casing is determined based on results of comparing a measured waveform and model waveforms. The measured waveform and model waveforms are generated based on operating an acoustic transmitter and an acoustic receiver within a wellbore comprising the well casing.

Abstract: In accordance with embodiments of the present disclosure, systems and methods for taking acoustic/ultrasonic wave measurements of a wellbore using a downhole tool equipped with microelectromechanical (MEM) transducers are provided. The MEM transducers may include a plurality of MEM transmitters (e.g., MEM speakers) and a plurality of separate MEM receivers (e.g., MEM microphones). These MEM transducers may be disposed in arrays proximate an outer surface of the downhole tool to collect acoustic/ultrasonic wave measurements of the full circumference of a wellbore. Due to their small size, large numbers of MEM transducers may be distributed radially around the downhole tool. Such an arrangement of sensors may enable the downhole tool to perform measurements of the entire wellbore without the downhole tool needing to be rotated, leading to an increased signal-to-noise ratio of the measurements.

Abstract: Systems, methods, and software for determining impedance of a casing-cement bond are described. In some aspects, the bond impedance is determined based on results of comparing a measured waveform and a model waveform. The model waveform corresponds to an estimated impedance of the bond and corresponds to a ray tracing of an acoustic signal that accounts for a radiation pattern of the acoustic transmitter and a curvature of the well casing. The measured waveform and the model waveform are generated based on operating an acoustic transmitter and an acoustic receiver within a wellbore comprising the well casing.

Abstract: In some implementations, a method for validating an acoustic bond-log tool includes having a test fixture including a wellbore casing emulating tubing. An outer tubing emulates a well formation and forms a perimeter of an annulus surrounding the wellbore casing emulating tubing. The wellbore casing tubing is configured with a stepped outer surface emulating different wellbore casing sidewall thicknesses. A dividing structure is coupled in the axial direction to the outer surface of the wellbore casing emulating tubing and to the inner surface of the outer tubing to radially subdivide the annulus into a plurality of hermetically sealable sample sections. Each sample section contains a sample of a material having a known acoustic impedance. The acoustic bond-log tool is validated by comparing a bond-log tool measurement of the acoustic impedance of each sample in a particular sample section to the known acoustic impedance of the sample.

Abstract: In accordance with embodiments of the present disclosure, systems and methods for taking acoustic/ultrasonic wave measurements of a wellbore using a downhole tool equipped with microelectromechanical (MEM) transducers are provided. The MEM transducers may include a plurality of MEM transmitters (e.g., MEM speakers) and a plurality of separate MEM receivers (e.g., MEM microphones). These MEM transducers may be disposed in arrays proximate an outer surface of the downhole tool to collect acoustic/ultrasonic wave measurements of the full circumference of a wellbore. Due to their small size, large numbers of MEM transducers may be distributed radially around the downhole tool. Such an arrangement of sensors may enable the downhole tool to perform measurements of the entire wellbore without the downhole tool needing to be rotated, leading to an increased signal-to-noise ratio of the measurements.

Abstract: Systems, methods, and software for determining properties of a medium surrounding an exterior portion of a well casing are described. In some aspects, the properties of the medium are determined based on measurements of detected acoustic energy and distances between one or more acoustic transmitters and two or more acoustic receivers. The measurements are obtained based on operating the transmitters and the receivers within a wellbore that includes the well casing.

Abstract: Systems, methods, and software for determining impedance of a casing-cement bond are described. In some aspects, the bond impedance is determined based on results of comparing a measured waveform and a model waveform. The model waveform corresponds to an estimated impedance of the bond and corresponds to a ray tracing of an acoustic signal that accounts for a radiation pattern of the acoustic transmitter and a curvature of the well casing. The measured waveform and the model waveform are generated based on operating an acoustic transmitter and an acoustic receiver within a wellbore comprising the well casing.

Abstract: In some implementations, a method for validating an acoustic bond-log tool includes having a test fixture including a wellbore casing emulating tubing. An outer tubing emulates a well formation and forms a perimeter of an annulus surrounding the wellbore casing emulating tubing. The wellbore casing tubing is configured with a stepped outer surface emulating different wellbore casing sidewall thicknesses. A dividing structure is coupled in the axial direction to the outer surface of the wellbore casing emulating tubing and to the inner surface of the outer tubing to radially subdivide the annulus into a plurality of hermetically sealable sample sections. Each sample section contains a sample of a material having a known acoustic impedance. The acoustic bond-log tool is validated by comparing a bond-log tool measurement of the acoustic impedance of each sample in a particular sample section to the known acoustic impedance of the sample.

Abstract: Systems, methods, and software for determining a thickness of a well casing are described. In some aspects, the thickness of the well casing is determined based on results of comparing a measured waveform and model waveforms. The measured waveform and model waveforms are generated based on operating an acoustic transmitter and an acoustic receiver within a wellbore comprising the well casing.

Abstract: In some embodiments, methods, apparatus, and systems may operate to launch acoustic waves along a first acoustic path length from an acoustic transducer. The apparatus receives a reflected signal in response to each acoustic wave, each reflected signal including at least one echo. The reflected signal is decomposed, using a time-frequency decomposition method with basis functions, into a wavelet associated with each echo. Parameters describing each associated wavelet are determined and a borehole evaluation or pipeline inspection is performed based on the parameters.

Abstract: Systems, methods, and software for determining properties of a medium surrounding an exterior portion of a well casing are described. In some aspects, the properties of the medium are determined based on measurements of detected acoustic energy and distances between one or more acoustic transmitters and two or more acoustic receivers. The measurements are obtained based on operating the transmitters and the receivers within a wellbore that includes the well casing.

Abstract: Systems, methods, and software for determining a thickness of a well casing are described. In some aspects, the thickness of the well casing is determined based on results of comparing a measured waveform and model waveforms. The measured waveform and model waveforms are generated based on operating an acoustic transmitter and an acoustic receiver within a wellbore comprising the well casing.