A method for determining a material in an annulus between two objects disposed in a borehole includes positioning logging tools in the borehole, each of the logging tools being oriented at a different angle. The method also includes measuring a property of the material in the annulus using the logging tools and determining the material in the annulus based on the measured property.

Method and apparatus for downhole photon imaging. The downhole photon imaging apparatus includes a photon source that emits photons; a scintillation device that generates a light signal in response to received photons; a light sensing device coupled with the scintillation device for generating an electronic signal in response to a received light signal; and a collimator coupled with the scintillation device which has a design that allows photons with single Compton backscattering and backscattered at a pre-determined backscattering angle to be detected by the scintillation device.

An x-ray-based borehole fluid evaluation tool for evaluating the characteristics of a fluid located external to said tool in a borehole using x-ray backscatter imaging is disclosed, the tool including at least an x-ray source; a radiation shield to define the output faun of the produced x-rays into the borehole fluid outside of the tool housing; at least one collimated imaging detector to record x-ray backscatter images; sonde-dependent electronics; and a plurality of tool logic electronics and power supply units. A method of using an x-ray-based borehole fluid evaluation tool to evaluate the characteristics of a fluid through x-ray backscatter imaging is also disclosed, the method including at least producing x-rays in a shaped output; measuring the intensity of backscatter x-rays returning from the fluid to each pixel of one or more array imaging detectors; and converting intensity data from said pixels into characteristics of the wellbore fluids.

A method and system for determining a density. The method may comprise disposing a nuclear density tool into a wellbore, performing a spectral deconvolution, determining an energy channel for a first measurement layer, recording a count rate with the gamma detector for the first measurement layer, applying a slope operator to the count rate, and identifying a first density of the first measurement layer. The system may comprise a nuclear density tool that includes a gamma source and a gamma detector configured to record a count rate, wherein the gamma detector and the gamma source are disposed on a longitudinal axis of the nuclear density tool. The system may also comprise an information handling system.

A method for determining a density may comprise disposing a nuclear density tool into a wellbore. The nuclear density tool may comprise a gamma source and a first gamma detector, wherein the first gamma detector and the gamma source are disposed on a longitudinal axis of the nuclear density tool. The method may further comprise transmitting an energy from the gamma source, detecting the energy reflected with the first gamma detector, recording a count rate of the energy at the first gamma detector, and identifying a density of a first layer from the count rate, a mass attenuation coefficient, and a source-to-detector distance. A system for determining a density may comprise a nuclear density tool. The nuclear density tool may comprise a gamma source configured to transmit an energy and a first gamma detector configured to detect reflected energy. The system may further comprise an information handling system.

A device and method for manipulating a robotic end effector in a well. Actuators manipulate the end effector independently through multiple degrees of freedom to improve the perspective of the end effector. An imaging sensor may be used to image, measure and identify features of a well and objects located therein. The sensor may be an ultrasound transducer, camera or x-ray sensor arranged radially, axial or distributed over a 2D surface. The end effector may be connected to a tool, such as a fishing tool, a welder, a milling tool, or a repair tool.

A method for determining a density may comprise disposing a nuclear density tool into a wellbore. The nuclear density tool may comprise a gamma source and a first gamma detector, wherein the first gamma detector and the gamma source are disposed on a longitudinal axis of the nuclear density tool. The method may further comprise transmitting an energy from the gamma source, detecting the energy reflected with the first gamma detector, recording a count rate of the energy at the first gamma detector, and identifying a density of a first layer from the count rate, a mass attenuation coefficient, and a source-to-detector distance. A system for determining a density may comprise a nuclear density tool. The nuclear density tool may comprise a gamma source configured to transmit an energy and a first gamma detector configured to detect reflected energy. The system may further comprise an information handling system.

Disclosed embodiments include a gamma logging detector assembly that includes a detector support structure comprising one or more high density alloy materials and including a first cylindrical drill collar segment and a second cylindrical drill collar segment each having a radius of at least R1. A third cylindrical drill collar segment is disposed axially between the first and second cylindrical drill collar segments to form an annular channel over the third cylindrical drill collar segment and between the first and second cylindrical drill collar segments. The third cylindrical drill collar segment includes an inwardly defined open cavity and a radius, R2, that is less than R1. An annular pressure sleeve comprising one or more low density alloy materials is disposed within the annular channel.

An x-ray-based reservoir evaluation tool for measurement variations in formation density anticipated at the water-oil interface of a reservoir is provided, the tool including at least: an internal length comprising a sonde section, wherein said sonde section further comprises an x-ray source; radiation measuring detectors; sonde-dependent electronics; and a plurality of tool logic electronics and PSUs. A method of using an x-ray based reservoir evaluation tool for measuring variations in formation density anticipated at the water-oil interface of a reservoir is also provided, the method including at least the following steps: using x-rays to illuminate the formation surrounding the cased borehole; uses detectors to directly measure the density of the formation; using detectors to directly measure the effects on the measurement from tool stand-off or production liner attenuation; and employing techniques for compensating for the production liner and liner-annular region when computing the saturated formation density within the production interval.

Through-tubing, cased-hole sealed material density can be evaluated using gamma ray measurements. Density evaluation comprises detecting, by at least one detector positioned within a casing of a wellbore including a sealing material positioned between the casing and a subsurface formation, electromagnetic radiation generated in response to nuclear radiation being emitted outward toward the subsurface formation, determining an electromagnetic radiation count based on the detected electromagnetic radiation, selecting at least one of a first reference material having a density that is less than a density of the sealing material and a second reference material having a density that is greater than the density of the sealing material, adjusting the electromagnetic radiation count based on the density of the at least one of the first reference material and the second reference material, and determining a density of the sealing material based on the adjusted electromagnetic radiation count.