Abstract: A method for remediating a microannulus in a cased wellbore may include conveying a downhole tool into the cased wellbore to a location of interest. The location of interest may include one or more perforations in a casing and a microannulus. The downhole tool may include a heat generation device. The method may also include activating the heat generation device to melt a fill material at the location of interest such that the fill material flows through the perforations into one or more voids, including the microannulus, in or around cement disposed between the casing and the cased wellbore. Additionally, the method may include deactivating the heat generation device to facilitate solidification of the fill material in the one or more voids and sealing of the microannulus.

Abstract: The disclosure relates to a method of determining at least a property of a material situated behind a casing of a borehole, wherein an image of a imaging parameter of the material, such as acoustic impedance, has been obtained. The method comprising identifying zones of the image corresponding to disturbance zones, based in particular on values of the imaging parameters or other measured parameters, deleting the data of the imaging parameter in each of the disturbance zones, reconstructing for each zone, data of the imaging parameter from the data of imaging parameter at the neighboring zones, and determining at least a property of the material based on the reconstructed image.

Abstract: Methods arc provided for using sonic tool data to investigate a multi-string wcllbore. The sonic data is processed to obtain indications of phase slowness dispersions for multiple locations in the wellbore. The dispersions are aggregated. The aggregated dispersions are compared with a plurality of cut-off mode templates to identify the presence of cut-off modes or the lack thereof in the aggregated phase slowness dispersions. Features of the multi-string wellbore are identified based on the presence of the cut-off modes or the lack thereof. In another method, the sonic data is processed to obtain indications as a function of depth of at least one of an energy spectrum, a semblance projection, a slowness dispersion projection, an attenuation dispersion projection, and a wavenumber dispersion projection. The indications are inspected to locate a shift at a particular depth indicat- ing a transition in at least oneannulus of the multi-string wellbore.

Abstract: Methods and systems of barrier evaluation are disclosed. The method includes obtaining vibration measurement data measured in a wellbore having at least one casing. In addition, the method includes determining a boundary definition of the barrier between the casing and a formation, based on the vibration measurement data. Further, the method includes evaluating the barrier based on the one boundary definition. The system includes a vibration sensor located in the wellbore having at least one casing and a vibration source for generating vibrations. The system may also include a data logging system of producing vibration measurement data received with the vibration sensor and a processor for determining at least one boundary definition of barrier between the casing and a formation, based on the vibration measurement data and evaluating the barrier based on the at least one boundary definition.

Abstract: A method for remediating a microannulus in a cased wellbore may include conveying a downhole tool into the cased wellbore to a location of interest. The location of interest may include one or more perforations in a casing and a microannulus. The downhole tool may include a heat generation device. The method may also include activating the heat generation device to melt a fill material at the location of interest such that the fill material flows through the perforations into one or more voids, including the microannulus, in or around cement disposed between the casing and the cased wellbore. Additionally, the method may include deactivating the heat generation device to facilitate solidification of the fill material in the one or more voids and sealing of the microannulus.

Abstract: A method of model-based acoustic measurements for a wellbore is disclosed. The method comprises creating an interpretation chart of acoustic measurements by a downhole tool in a wellbore using a numerical modeling and performing an evaluation with respect to the wellbore based on the interpretation chart.

Abstract: Systems, methods, and devices for evaluating proper cement installation in a well are provided. In one example, a method includes receiving acoustic cement evaluation data into a data processing system. The acoustic cement evaluation data derives from one or more acoustic downhole tools used over a depth interval in a well having a casing. The acoustic cement evaluation data includes sonic measurements and ultrasonic measurements. The method includes deriving a sonic-derived acoustic impedance Z(sonic) from the sonic measurements deriving an ultrasonic-derived acoustic impedance Z(ultrasonic) from the ultrasonic measurements comparing the Z(sonic) with respect to the Z(ultrasonic), and determining whether an annular fill behind the casing is well bonded, partially bonded, comprises wet microannulus, or comprises dry microannulus based on the comparison of the Z(sonic) with respect to the Z(ultrasonic).

Abstract: Methods and systems of barrier evaluation are disclosed. The method includes obtaining vibration measurement data measured in a wellbore having at least one casing. In addition, the method includes determining a boundary definition of the barrier between the casing and a formation, based on the vibration measurement data. Further, the method includes evaluating the barrier based on the one boundary definition. The system includes a vibration sensor located in the wellbore having at least one casing and a vibration source for generating vibrations. The system may also include a data logging system of producing vibration measurement data received with the vibration sensor and a processor for determining at least one boundary definition of barrier between the casing and a formation, based on the vibration measurement data and evaluating the barrier based on the at least one boundary definition.

Abstract: Systems, methods, and devices for evaluating proper cement installation in a well are provided. In one example, a method includes receiving acoustic cement evaluation data having a first parameterization. At least a portion of the entire acoustic cement evaluation data may be corrected to account for errors in the first parameterization, thereby obtaining corrected acoustic cement evaluation data. This corrected acoustic cement evaluation data may be processed with an initial solid-liquid-gas model before performing a posteriori refinement of the initial solid-liquid-gas model, thereby obtaining a refined solid-liquid-gas model. A well log track-indicating whether a material behind the casing is a solid, liquid, or gas-may be generated by processing the corrected acoustic cement evaluation data using the refined solid-liquid-gas model.