Abstract: A method includes introducing a tool string into a wellbore having material disposed in an annular region surrounding the casing. Obtaining acoustic refracted waveform measurements of the material from a cement bond logging tool, obtaining ultrasonic measurements of the material from a circumferential acoustic scanning tool, obtaining gamma radiation measurements scattered from the material from a circumferential spectral density logging (RSDX) tool by emitting gamma radiation from a radioactive source in a rotating portion of the RSDX and detecting scattered gamma radiation using near and far spectral density detectors, and obtaining thermal neutron radiation measurements scattered from the material from a dual spaced neutron logging tool. A computer obtains measurements and generates a deliverable that includes one or more cross plots that identify a compositional equivalent of the material in an entire circumference of the wellbore.

Abstract: A method includes introducing a tool string into a wellbore having annular material disposed in an annulus defined between casing and the wellbore. Obtaining acoustic refracted waveform measurements of the annular material from a cement bond logging tool, obtaining ultrasonic measurements of the annular material from a circumferential acoustic scanning tool, obtaining gamma radiation measurements scattered from the annular material from a spectral density logging tool, and obtaining thermal neutron radiation measurements scattered from the annular material from a dual spaced neutron logging tool. Obtained measurements may then be collected and computed with a computer and a deliverable is generated that includes one or more cross plots providing a compositional equivalent of the annular material.

Abstract: A method includes introducing a tool string into a wellbore having material disposed in an annular region surrounding the casing. Obtaining acoustic refracted waveform measurements of the material from a cement bond logging tool, obtaining ultrasonic measurements of the material from a circumferential acoustic scanning tool, obtaining gamma radiation measurements scattered from the material from a circumferential spectral density logging (RSDX) tool by emitting gamma radiation from a radioactive source in a rotating portion of the RSDX and detecting scattered gamma radiation using near and far spectral density detectors, and obtaining thermal neutron radiation measurements scattered from the material from a dual spaced neutron logging tool. A computer obtains measurements and generates a deliverable that includes one or more cross plots that identify a compositional equivalent of the material in an entire circumference of the wellbore.

Abstract: A method for evaluating a cement sheath in a wellbore, in some embodiments, comprises transmitting sonic or ultrasonic waves from a logging tool disposed in a wellbore, receiving reflected waves at the logging tool and recording waveforms based on the received waves, processing the waveforms to determine average absolute value amplitude data for each of a plurality of zones, and determining a number using average absolute value amplitude data for a first of the plurality of zones and average absolute value amplitude data for a second of the plurality of zones.

Abstract: A method for generating a cement bond log, in some embodiments, comprises transmitting sonic or ultra-sonic waves in multiple directions from a logging tool disposed in a wellbore, receiving reflected waves at the logging tool and recording waveforms based on the received waves, processing the waveforms to determine numerical values that indicate a degree of bonding associated with multiple portions of a cement sheath disposed in the wellbore, aggregating the numerical values, and generating a composite image based on the aggregated numerical values.

Abstract: A cement bond log from recorded ultrasonic waveforms, a method for evaluating bonding of cement in a wellbore between a casing and a wellbore wall, and a method for creating a cement bond log from recorded ultrasonic waveforms are disclosed, in which series of points corresponding to maxima and minima of the waveforms are identified. Absolute value amplitudes of the series of points are thereafter identified and a correlation thereof is analyzed to divide each series of points into four or more zones, corresponding to casing arrival data, inner and outer annular data, wellbore wall arrival data, respectively. Mean values of the absolute value amplitudes of the waveforms for points of each series falling within each of the four zones are calculated, which relate to cement bonding at the depths of the recorded ultrasonic waveforms.

Abstract: An apparatus includes a tool configured to operate within a borehole during a period wherein matter is being output from a surrounding earth formation into a flow of matter in the borehole. The tool includes a main tool body having a longitudinal axis. A temperature probe array is coupled to the main tool body, including a first temperature probe and a second temperature probe. The first temperature probe is radially spaced from and is at a different circumferential position relative to the second temperature probe during operation. The first temperature probe and the second temperature probe are configured to measure a first temperature and a second temperature, respectively, during operation, wherein at least one of a type of matter in the flow and an entry point of the matter from the surrounding earth formation is derived using the first temperature and the second temperature.

Abstract: Casing removal operations may utilize an analytical model to the estimate the total force to (1) break bonding between a cut casing and the annular materials contained between the cut casing and the surrounding borehole and (2) pull the cut casing upward through the borehole while taking into account frictional forces inside and outside the cut casing, shear forces, and the like. Such models may further predict the casing overpull and total tension needed to extract the cut casing from the borehole. Using these models in conjunction with the specifications of the casing retrieval equipment may allow for determining the cutting depth for producing the cut casing with higher accuracy than previously available.

Abstract: A method for generating a cement bond log, in some embodiments, comprises transmitting sonic or ultra-sonic waves in multiple directions from a logging tool disposed in a wellbore, receiving reflected waves at the logging tool and recording waveforms based on the received waves, processing the waveforms to determine numerical values that indicate a degree of bonding associated with multiple portions of a cement sheath disposed in the wellbore, aggregation the numericakl value, and generating a composite image based on the aggregated numerical values.

Abstract: A method for evaluating a cement sheath in a wellbore, in some embodiments, comprises transmitting sonic or ultrasonic waves from a logging tool disposed in a wellbore, receiving reflected waves at the logging tool and recording waveforms based on the received waves, processing the waveforms to determine average absolute value amplitude data for each of a plurality of zones, and determining a number using average absolute value amplitude data for a first of the plurality of zones and average absolute value amplitude data for a second of the plurality of zones.

Abstract: A cement bond log from recorded ultrasonic waveforms, a method for evaluating bonding of cement in a wellbore between a casing and a wellbore wall, and a method for creating a cement bond log from recorded ultrasonic waveforms are disclosed, in which series of points corresponding to maxima and minima of the waveforms are identified. Absolute value amplitudes of the series of points are thereafter identified and a correlation thereof is analyzed to divide each series of points into four or more zones, corresponding to casing arrival data, inner and outer annular data, wellbore wall arrival data, respectively. Mean values of the absolute value amplitudes of the waveforms for points of each series falling within each of the four zones are calculated, which relate to cement bonding at the depths of the recorded ultrasonic waveforms.

Abstract: A method includes introducing a tool string into a wellbore having annular material disposed in an annulus defined between casing and the wellbore. Obtaining acoustic refracted waveform measurements of the annular material from a cement bond logging tool, obtaining ultrasonic measurements of the annular material from a circumferential acoustic scanning tool, obtaining gamma radiation measurements scattered from the annular material from a spectral density logging tool, and obtaining thermal neutron radiation measurements scattered from the annular material from a dual spaced neutron logging tool. Obtained measurements may then be collected and computed with a computer and a deliverable is generated that includes one or more cross plots providing a compositional equivalent of the annular material.

Abstract: Casing removal operations may utilize an analytical model to the estimate the total force to (1) break bonding between a cut casing and the annular materials contained between the cut casing and the surrounding borehole and (2) pull the cut casing upward through the borehole while taking into account frictional forces inside and outside the cut casing, shear forces, and the like. Such models may further predict the casing overpull and total tension needed to extract the cut casing from the borehole. Using these models in conjunction with the specifications of the casing retrieval equipment may allow for determining the cutting depth for producing the cut casing with higher accuracy than previously available.

Abstract: An apparatus includes a tool configured to operate within a borehole during a period wherein matter is being output from a surrounding earth formation into a flow of matter in the borehole. The tool includes a main tool body having a longitudinal axis. A temperature probe array is coupled to the main tool body, including a first temperature probe and a second temperature probe. The first temperature probe is radially spaced from and is at a different circumferential position relative to the second temperature probe during operation. The first temperature probe and the second temperature probe are configured to measure a first temperature and a second temperature, respectively, during operation, wherein at least one of a type of matter in the flow and an entry point of the matter from the surrounding earth formation is derived using the first temperature and the second temperature.

Abstract: Methods for determining formation characteristics comprising establishing baseline casing conditions for a string of casing disposed within a wellbore in a formation and measuring updated casing conditions for the string of casing at a first time interval from the establishing of the baseline casing conditions. The baseline casing conditions are compared to the updated casing conditions to determine changes in the string of casing over the first time interval. These changes in the string of casing are then used to determine formation characteristics.

Abstract: Methods for determining formation characteristics comprising establishing baseline casing conditions for a string of casing disposed within a wellbore in a formation and measuring updated casing conditions for the string of casing at a first time interval from the establishing of the baseline casing conditions. The baseline casing conditions are compared to the updated casing conditions to determine changes in the string of casing over the first time interval. These changes in the string of casing are then used to determine formation characteristics.