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: 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 parameterized using a first parameterization. A subset of the acoustic cement evaluation data is compared to expected nominal values of the acoustic cement evaluation data. When the subset of the acoustic cement evaluation data does not substantially conform to the expected nominal values of the acoustic cement evaluation data, all or part of the acoustic cement evaluation data is corrected to cause the subset of the acoustic cement evaluation data to more closely match the expected nominal values of the acoustic cement evaluation data. The corrected acoustic cement evaluation data may be used to estimate a presence of solids, liquids, and/or gases behind the casing.

Abstract: Systems and methods for determining annular fill material using resistivity measurements are provided. In one example, a method is provided. The method may include placing a downhole tool into a cased well. The well may include an annulus located between a casing and a formation. The method may also include determining, by the downhole tool, resistivity measurements associated with portions of the well. Furthermore, the method may include identifying, by a computer, based at least in part on the resistivity measurements, the presence of annular fill materials in the well. Additionally, the method may include determining, by the computer based at least in part on the resistivity measurements, respective locations of the annular fill materials in the well.

Abstract: Apparatus and method for characterizing a barrier installed in a borehole traversing a formation including locating an acoustic tool with a receiver and a transmitter at a location in the borehole, activating the acoustic tool to form acoustic waveforms, wherein the receiver records the acoustic waveforms, and processing the waveforms to identify barrier parameters as a function of azimuth and depth along the borehole, wherein the waveforms comprise at least two of sonic signals, ultrasonic pulse-echo signals, and ultrasonic pitch-catch signals.

Abstract: Systems, methods, and devices for evaluating proper cement installation in a well are provided. In one example, a method includes obtaining acoustic cement evaluation data points and processing the acoustic cement evaluation data points using a solid-liquid-gas model to assign at least some of the acoustic cement evaluation data points to a material of solid, liquid, or gas in an annulus of the wellbore behind the casing. The solid-liquid-gas model includes a tight solid-liquid-gas model in which a gas threshold range is not directly adjacent to a liquid threshold range and/or a solid-liquid-gas model that considers flexural attenuation when a pulse-echo-derived acoustic impedance is below an evanescence point.

Abstract: A method of testing a barrier in a wellbore that includes isolating a volume in the wellbore between an isolation device connected with an apparatus and the barrier, and pressure testing the barrier using the apparatus to adjust the pressure in the volume.

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 parameterized using a first parameterization. A subset of the acoustic cement evaluation data is compared to expected nominal values of the acoustic cement evaluation data. When the subset of the acoustic cement evaluation data does not substantially conform to the expected nominal values of the acoustic cement evaluation data, all or part of the acoustic cement evaluation data is corrected to cause the subset of the acoustic cement evaluation data to more closely match the expected nominal values of the acoustic cement evaluation data. The corrected acoustic cement evaluation data may be used to estimate a presence of solids, liquids, and/or gases behind the casing.

Abstract: Systems, methods, and devices for evaluating proper cement installation in a well are provided. In one example, a method includes obtaining acoustic cement evaluation data points and processing the acoustic cement evaluation data points using a solid-liquid-gas model to assign at least some of the acoustic cement evaluation data points to a material of solid, liquid, or gas in an annulus of the wellbore behind the casing. The solid-liquid-gas model includes a tight solid-liquid-gas model in which a gas threshold range is not directly adjacent to a liquid threshold range and/or a solid-liquid-gas model that considers flexural attenuation when a pulse-echo-derived acoustic impedance is below an evanescence point.

Abstract: Systems and methods for determining annular fill material using resistivity measurements are provided. In one example, a method is provided. The method may include placing a downhole tool into a cased well. The well may include an annulus located between a casing and a formation. The method may also include determining, by the downhole tool, resistivity measurements associated with portions of the well. Furthermore, the method may include identifying, by a computer, based at least in part on the resistivity measurements, the presence of annular fill materials in the well. Additionally, the method may include determining, by the computer based at least in part on the resistivity measurements, respective locations of the annular fill materials in the well.

Abstract: Systems and methods for enhancing local heterogeneity of cased-hole well logging information are provided. An example of such a cased-hole well logging system may include a downhole tool and data processing circuitry. The downhole tool may obtain cased-hole logging information over a depth of a cased wellbore. The data processing circuitry may normalize at least some of the cased-hole logging information over at least a first subsection of the depth and may map visualization indicators to the normalized cased-hole logging information. The mapping of the visualization indicators to the normalized cased-hole logging information may enable an analyst to identify casing and/or annulus material properties not readily apparent using exclusively absolute visualizations of the cased-hole logging information.

Abstract: Apparatus and method for characterizing a barrier installed in a borehole traversing a formation including locating an acoustic tool with a receiver and a transmitter at a location in the borehole, activating the acoustic tool to form acoustic waveforms, wherein the receiver records the acoustic waveforms, and processing the waveforms to identify barrier parameters as a function of azimuth and depth along the borehole, wherein the waveforms comprise at least two of sonic signals, ultrasonic pulse-echo signals, and ultrasonic pitch-catch signals.

Abstract: A method of testing a barrier in a wellbore that includes isolating a volume in the wellbore between an isolation device connected with an apparatus and the barrier, and pressure testing the barrier using the apparatus to adjust the pressure in the volume.

Abstract: A method for evaluating wellbore integrity including introducing a drill to a surface of a casing encompassing an annulus, enclosing the drill in a housing hydraulically isolating the surface, drilling through the casing and into cement surrounding the casing, observing a pressure of the fluid, and using the pressure observation and a drill position to evaluate a presence of a defect and a location of the defect. Apparatus for evaluating wellbore integrity including a probe comprising a drill, wherein the probe is hydraulically isolated from the wellbore, a valve that encompasses the drill, a pressure gauge to measure the pressure of the fluid within the housing, a pressure gauge to measure the pressure in the system outside the housing, and equipment to compare the pressure measurements and the position of the drill and to evaluate a presence and a location of the defect.

Abstract: A method for evaluating wellbore integrity including introducing a drill to a surface of a casing encompassing an annulus, enclosing the drill in a housing hydraulically isolating the surface, drilling through the casing and into cement surrounding the casing, observing a pressure of the fluid, and using the pressure observation and a drill position to evaluate a presence of a defect and a location of the defect. Apparatus for evaluating wellbore integrity including a probe comprising a drill, wherein the probe is hydraulically isolated from the wellbore, a valve that encompasses the drill, a pressure gauge to measure the pressure of the fluid within the housing, a pressure gauge to measure the pressure in the system outside the housing, and equipment to compare the pressure measurements and the position of the drill and to evaluate a presence and a location of the defect.