Abstract: A system and method for detecting defects in a tubular structure installed in a wellbore extending into a subterranean formation. An input image of the tubular structure contains input data indicative of a characteristic of the tubular structure. A background image is determined based on the input image. The background image contains background data indicative of the characteristic of the tubular structure associated with manufacturing of the tubular structure. A defect image is determined based on a difference between the input image and the background image. The defect image contains defect data indicative of the characteristic of the tubular structure associated with defects in the tubular structure.

Abstract: Systems and methods are provided for obtaining a flexural-attenuation measurement for cement evaluation that may be effective even for wells with relatively thick casings. A method includes emitting an acoustic signal at a casing in a well that excites the casing into generating an acoustic response signal containing acoustic waves, such as Lamb waves. The Lamb waves include flexural waves and extensional waves. The casing may be relatively large, having a thickness of at least 16 mm. The acoustic response signal may be detected and filtered to reduce a relative contribution of the extensional waves. This may correspondingly increase a relative contribution of the flexural waves. The filtered acoustic response signal may be used as a flexural-attenuation measurement for cement evaluation.

Abstract: A system for wireline service planning and advising includes a receiver, one or more computing system processors, and a transmitter. The receiver is configured to receive, from a user of the system, an objective parameter for interpreting a state of a well barrier. The one or more computing system processors is in communication with the receiver and configured to generate a plurality of candidate services based on the objective parameter and a model of the well barrier, each candidate service specifying sensor data to be acquired using wireline tools, select at least one wireline service from the wireline candidate services based on a selection logic or input by the user, and generate an execution plan specifying operational parameters of the selected wireline service. The transmitter is in communication with the one or more computing system processors and configured to transmit the execution plan to execute the selected wireline service at a wellsite.

Abstract: A system for wireline service planning and advising includes a receiver, one or more computing system processors, and a transmitter. The receiver is configured to receive, from a user of the system, an objective parameter for interpreting a state of a well barrier. The one or more computing system processors is in communication with the receiver and configured to generate a plurality of candidate services based on the objective parameter and a model of the well barrier, each candidate service specifying sensor data to be acquired using wireline tools, select at least one wireline service from the wireline candidate services based on a selection logic or input by the user, and generate an execution plan specifying operational parameters of the selected wireline service. The transmitter is in communication with the one or more computing system processors and configured to transmit the execution plan to execute the selected wireline service at a wellsite.

Abstract: Systems and methods are provided for obtaining a flexural-attenuation measurement for cement evaluation that may be effective even for wells with relatively thick casings. A method includes emitting an acoustic signal at a casing in a well that excites the casing into generating an acoustic response signal containing acoustic waves, such as Lamb waves. The Lamb waves include flexural waves and extensional waves. The casing may be relatively large, having a thickness of at least 16 mm. The acoustic response signal may be detected and filtered to reduce a relative contribution of the extensional waves. This may correspondingly increase a relative contribution of the flexural waves. The filtered acoustic response signal may be used as a flexural-attenuation measurement for cement evaluation.

Abstract: Acoustic imaging waveforms are measured utilizing a downhole acoustic tool within a wellbore, and then aligned relative to a main echo of each waveform. The aligned waveforms are then subjected to a first low-pass filter. Residuals are extracted by determining differences between the aligned waveforms and the filtered waveforms. The residuals are aligned to corresponding acoustic firing pulses of the downhole acoustic tool. The aligned residuals are subjected to a second low-pass filter. The measured waveforms are aligned to the corresponding acoustic firing pulses. Noise associated with the downhole acoustic tool is removed from the pulse-aligned, measured waveforms utilizing the filtered residuals.

Abstract: Acoustic imaging waveforms are measured utilizing a downhole acoustic tool within a wellbore, and then aligned relative to a main echo of each waveform. The aligned waveforms are then subjected to a first low-pass filter. Residuals are extracted by determining differences between the aligned waveforms and the filtered waveforms. The residuals are aligned to corresponding acoustic firing pulses of the downhole acoustic tool. The aligned residuals are subjected to a second low-pass filter. The measured waveforms are aligned to the corresponding acoustic firing pulses. Noise associated with the downhole acoustic tool is removed from the pulse-aligned, measured waveforms utilizing the filtered residuals.

Abstract: Systems and methods are provided for obtaining a flexural-attenuation measurement for cement evaluation that may be effective even for wells with relatively thick casings. A method includes emitting an acoustic signal at a casing in a well that excites the casing into generating an acoustic response signal containing acoustic waves, such as Lamb waves. The Lamb waves include flexural waves and extensional waves. The casing may be relatively large, having a thickness of at least 16 mm. The acoustic response signal may be detected and filtered to reduce a relative contribution of the extensional waves. This may correspondingly increase a relative contribution of the flexural waves. The filtered acoustic response signal may be used as a flexural-attenuation measurement for cement evaluation.

Abstract: A method includes performing pulse echo measurements using a pulse echo tool. The method also includes detecting a casing collar using the pulse echo measurements performed by the pulse echo tool. The method further includes estimating a tool response of the pulse echo tool response at the casing collar using one or more processors based on the pulse echo measurement at the casing collar. The method also includes and removing the pulse echo tool response estimation from at least some of the pulse echo measurements not at the casing collar.

Abstract: Systems, methods, and devices for compensating for environmental conditions on electromagnetic measurements are provided. For example, a downhole logging tool may include a first transmitter coil, a second transmitter coil, and a first receiver coil. The first transmitter coil may provide a first magnetic signal in a wellbore having a conductive casing. The second transmitter coil may provide a second magnetic signal in the wellbore. The first receiver may obtain a first measurement relating to the first magnetic signal and a second measurement relating to the second magnetic signal. The first receiver coil may be near enough to the first transmitter coil and the second transmitter coil to obtain measurements predominantly in the near field eddy current regime. A ratio of the first measurement and the second measurement may cancel environmental dependencies of the first receiver coil.

Abstract: Methods for separating flexural and extensional mode signals from a multi-modal signal are provided. In one embodiment, a method includes emitting an ultrasonic pulse to excite a multi-modal Lamb wave in a pipe and then detecting acoustic signals generated from the Lamb wave. The detected acoustic signals are processed to separate the extensional and flexural mode signals. This processing can include filtering the detected acoustic signals with filters that are based on quality factors and dispersion characteristics for the individual modes to produce sets of coefficients, selecting subsets of the coefficients, and using the selected subsets to predict extensional and flexural mode waveforms that are based on the estimated quality factors for the individual modes. Additional methods, systems, and devices are also disclosed.

Abstract: A method includes performing pulse echo measurements using a pulse echo tool. The method also includes detecting a casing collar using the pulse echo measurements performed by the pulse echo tool. The method further includes estimating a tool response of the pulse echo tool response at the casing collar using one or more processors based on the pulse echo measurement at the casing collar. The method also includes and removing the pulse echo tool response estimation from at least some of the pulse echo measurements not at the casing collar.

Abstract: Techniques involve methods and systems for separating leaky-Lamb modes to evaluate cylindrically layered structures. Embodiments involve receiving acoustic cement evaluation data from one or more acoustic downhole tools used over a depth interval in a well having a casing. The acoustic cement evaluation data includes leaky-Lamb wave measurements measured from the acoustic downhole tools. Embodiments also involve determining an extensional mode component and a flexural mode component of the leaky-Lamb wave measurements and determining a flexural wave attenuation based on the flexural mode component of the leaky-Lamb wave measurement. In some embodiments, the extensional and flexural mode components can be determined using mode decomposition technique.

Abstract: Embodiments of the disclosure may include systems and methods for evaluating gas-contaminated cement. In one embodiment, a vector-valued image of cement state probability may be obtained from an acoustic logging tool, and a maximum a posterior classification of cement state of the vector-valued image may be determined. A vector probability diffusion equation may be used to minimize the total variation of the vector-valued image over a number of interactions to produce a second image. The maximum a posterior classification of cement state the second image may be determined and compared to the maximum a posterior classification of cement state of the vector-valued image. Depending on the comparison, the original image and cement state may be used or a new gas-contaminated image with a different cement state may be generated.

Abstract: Systems, methods, and devices for compensating for environmental conditions on electromagnetic measurements are provided. For example, a downhole logging tool may include a first transmitter coil, a second transmitter coil, and a first receiver coil. The first transmitter coil may provide a first magnetic signal in a wellbore having a conductive casing. The second transmitter coil may provide a second magnetic signal in the wellbore. The first receiver may obtain a first measurement relating to the first magnetic signal and a second measurement relating to the second magnetic signal. The first receiver coil may be near enough to the first transmitter coil and the second transmitter coil to obtain measurements predominantly in the near field eddy current regime. A ratio of the first measurement and the second measurement may cancel environmental dependencies of the first receiver coil.

Abstract: An ultrasonic estimating method and apparatus are presented for estimating a mud velocity in a casing including a transducer and adapted to be positioned inside the casing and displaced through the casing at a plurality of azimuth and a plurality of depths.

Abstract: A well casing is insonified with a first acoustic wave in a first mode that may be any mode of a set including: extensional mode, thickness mode, flexural mode. A first echo is received at a first acoustic transducer for receiving, a first signal is produced and a first measurement is extracted from the first signal. The casing is then insonified with a second acoustic wave in a second mode that may be any mode of the set of modes but is distinct from the first mode. A second echo is received at a selected second acoustic transducer for receiving and a second signal is produced. A second measurement is extracted from the second signal. The zone behind the casing of the well is evaluated from a combination of the first measurement and the second measurement.

Abstract: An ultrasonic estimating method for estimating a mud velocity flowing into a casing by means of an ultrasonic estimating apparatus comprising a transducer and adapted to be positioned inside the casing and displaced through the casing at a plurality of azimuth and a plurality of depth, the method comprising the steps of: a) for a first depth and a first azimuth of the ultrasonic measuring arrangement: a1) emitting an emission ultrasonic wave towards the casing for exciting the casing with a sensibly normal incidence, a2) receiving a reflection ultrasonic wave reflected from the casing, a3) measuring a transit time Ti MES between the emitting step and the receiving step, a4) determining the casing thickness th1 for the first azimuth, b) repeating the emitting step a1), the receiving step a2), the measuring step a3) and the determining step a4) for the first depth and at least a second azimuth of the ultrasonic measuring arrangement, c) calculating an intermediate mud velocity value Vmud CALC based on the m

Abstract: The invention provides a method for estimating an impedance of a material behind a casing wall, wherein the casing is disposed in a borehole drilled in a geological formation, and wherein a borehole fluid is filling said casing, the material being disposed in an annulus between said casing and said geological formation, said method using a logging tool positionable inside the casing and said method comprising: exciting a first acoustic wave in said casing by insonifying said casing with a first pulse, the first acoustic wave having a first mode that may be one of flexural mode or extensional mode; receiving one or more echoes from said first acoustic wave, and producing a first signal; extracting from said first signal a first equation with two acoustic properties unknowns for respectively said material and said borehole fluid; exciting a second acoustic wave in said casing by insonifying said casing with a second pulse, the second acoustic wave having a thickness mode; receiving one or more echoes from said

Abstract: A well casing is insonified with a first acoustic wave in a first mode that may be any mode of a set including: extensional mode, thickness mode, flexural mode. A first echo is received at a first acoustic transducer for receiving, a first signal is produced and a first measurement is extracted from the first signal. The casing is then insonified with a second acoustic wave in a second mode that may be any mode of the set of modes but is distinct from the first mode. A second echo is received at a selected second acoustic transducer for receiving and a second signal is produced. A second measurement is extracted from the second signal. The zone behind the casing of the well is evaluated from a combination of the first measurement and the second measurement.