Abstract: A method and system for creating a pulsing scheme. The method may include selecting a pulsing scheme for downhole measurements using a pulsed neutron logging tool and selecting a neutron burst width for the pulsing scheme based at least in part on a neutron tube utilized by the pulsed neutron logging tool during the downhole measurements. The method may further include selecting a carbon-oxygen ratio (CO) neutron burst train for the pulsing scheme to be utilized by the neutron tube, selecting a Sigma decay time for the pulsing scheme, and performing one or more measurements with the pulsed neutron logging tool using the pulsing scheme. The system may include a pulsed neutron logging tool. The pulsed neutron logging tool may include a neutron tube disposed in a pulsed neutron generator, one or more gamma ray scintillator detectors, and one or more thermal neutron detectors.

Abstract: A method and systems for taking downhole measurements. The method may include selecting a pulsing scheme for taking one or more measurements using a pulsed neutron logging tool, selecting a neutron burst width for the pulsing scheme based at least in part on a neutron tube utilized by the pulsed neutron logging tool to form at least in part a neutron burst train, and selecting a decay window in which the one or more measurements are performed by the pulsed neutron logging tool. The method may further include selecting a starting time for a late gate in which the one or measurements are taken, disposing the pulsed neutron logging tool into a borehole, performing the neutron burst train with the pulsed neutron logging tool, and performing the one or more measurements with the pulsed neutron logging tool during the late gate.

Abstract: Provided are a system and a method for positioning a suspected article. The system includes a truss indicating mechanism defining a coordinate system having X, Y and Z directions perpendicular to each other. The truss indicating mechanism includes a first direction moving rail disposed on a truss body in one of the three directions; a second direction moving rail movably disposed on the first direction moving rail in a another of the three directions, the second direction moving rail is movable in the first direction relative to the first direction moving rail; and a ranging indicating device movably disposed on the second direction moving rail, the ranging indicating device is configured to be movable in the second direction relative to the second direction moving rail, and is configured to feed back position information of the suspected article in a to-be-inspected cargo by using coordinate information of the coordinate system.

Abstract: A neutron generator with an ion source within a housing may be used for generating neutrons for neutron logging downhole in a wellbore. The ion source within the housing of the neutron generator may include a hot cathode, an ion source cylinder, a first grid separated from the ion source cylinder, and an extractor separated from the ion source cylinder, the extractor having a second grid.

Abstract: Systems and methods are provided for operating and constructing a neutron generator. In some examples, an ion source within a neutron generator may include a hot cathode; at least one cylindrical sleeve coupled to an exterior surface of the hot cathode; at least one electrode coupled to an interior surface of the neutron generator; and at least one mounting flange, wherein a proximal end of the at least one mounting flange is coupled to the at least one cylindrical sleeve and a distal end of the at least one mounting flange is coupled to the at least one electrode.

Abstract: Systems and techniques are provided for optimizing the performance of a target for a downhole neutron generator. An example method can include disposing a first source material and a first substrate in a vacuum chamber at an initial temperature, evaporating the first source material to be deposited onto a surface of the first substrate, monitoring a temperature of the first substrate during the evaporation of the first source material, and determining a thermal equilibrium process temperature at which the temperature of the first substrate is stabilized. The example method can further include disposing a second source material and a second substrate in the vacuum chamber at the thermal equilibrium process temperature, evaporating the second source material to be deposited onto a surface of the second substrate, and obtaining the second substrate deposited with the second source material for a target of a downhole neutron generator.

Abstract: A method for forming a neutron generating tube. The method may include brazing a welding ring to a neutron generating tube at a first open end, brazing a welding lip to a target rod, and disposing the target rod into the neutron generating tube, wherein the welding lip is at least in part in contact with the welding ring. The method may further include welding the welding lip to the welding ring to form a vacuum envelope, disposing a copper tubing at a second open end of the neutron generating tube opposite the first open end, and pinching off the copper tubing to form a sealed vacuum in the neutron generating tube.

Abstract: A method and system for identifying one or more petrophysical properties in a formation. The method and system may include disposing a pulsed-neutron logging tool into a borehole that is disposed in a formation, emitting a neutron from a neutron source on the pulsed-neutron logging tool into the formation, and capturing one or more gammas expelled from formation in response to the neutron from the neutron source to form a plurality of pulsed neutron logging (PNL) measurements in a log. The method and system may further include comparing the log to a database with a cost function to form a solution; and identifying a plurality of petrophysical properties based at least in part on the solution.

Abstract: The techniques as described herein enhance the accuracy and precision of mineralogy analysis in elemental spectroscopy logging by utilizing oxide standards and/or rock-forming mineral compounds as reference materials that provide more representative and realistic signatures of geological formations. A method comprises logging a wellbore with a tool and fitting reference spectra from oxide compounds and/or rock-forming mineral compounds against measured gamma spectra obtained with the tool, to characterize a subterranean formation that the wellbore extends through.

Abstract: The techniques as described herein result in a single set of intrinsic carbon-oxygen (CO) measurements that can be used for various borehole and formation saturation conditions, enhancing the reliability and robustness of formation evaluation in oil and gas wells. A method comprises formulating an intrinsic CO ratio for a subterranean formation, based on theoretical atomic concentrations of carbon and oxygen, and porosity and fluid saturation parameters.

Abstract: Some disclosed embodiments are directed to methods and systems for performing pair-wise delta compression. For example, systems obtain a set of files to be compressed into a single compressed file. The system identifies different attributes related to the set of files. For each file in the set of files, the system predicts an optimized set of candidate compression files and calculates a delta between each file in the optimized set and the target file corresponding to the optimized set. After identifying the smallest delta, the system compresses the selected pair of files associated with the smallest delta in order to generate the single compressed file for the set of files.

Abstract: Aspects of the subject technology relate to performing gamma spectral analysis based on machine learning. Gamma spectrum data, which can be associated with a gamma spectrum can be gathered. The gamma spectrum data can include an energy channel and a count rate for gamma rays detected by one or more gamma detectors. A spectral image can be constructed based on the gamma spectrum data. One or more machine learning models can be trained based on the spectral image. Additionally, one or more features of the gamma spectrum can be extracted from the spectral image through the one or more machine learning models.

Abstract: Some disclosed embodiments are directed to methods and systems for performing pair-wise delta compression. For example, systems obtain a set of files to be compressed into a single compressed file. The system identifies different attributes related to the set of files. For each file in the set of files, the system predicts an optimized set of candidate compression files and calculates a delta between each file in the optimized set and the target file corresponding to the optimized set. After identifying the smallest delta, the system compresses the selected pair of files associated with the smallest delta in order to generate the single compressed file for the set of files.

Abstract: Aspects of the subject technology relate to determining holdup compensated formation saturation while refraining from calculating holdup. Inelastic gamma spectrum data for an inelastic gamma spectrum generated downhole in a wellbore can be accessed. Further, capture gamma spectrum data for one or more capture gamma spectrums generated downhole in the wellbore can be accessed. A model that accounts for holdup measurement can be applied to both the inelastic gamma spectrum data and the capture gamma spectrum data to identify a compensated oil saturation for a formation surrounding at least a portion of the wellbore based on both the inelastic gamma spectrum and the one or more capture gamma spectrums.

Abstract: A method includes operating a neutron generator in a loading mode by ionizing ionizable gas within an ion source of the neutron generator to create a plurality of ions, and accelerating the plurality of ions by providing a first voltage to a target rod that supports the target to create a first ion beam that bombards a target of the neutron generator. The method also includes operating the neutron generator in a generating mode to generate a plurality of neutrons by accelerating the plurality of ions by providing a second voltage to the target rod to create a second ion beam that bombards the target. The second voltage is greater than the first voltage.

Abstract: A conveying device (100) and an inspection system (1000) are provided. The conveying device includes: a first support frame (1); a first conveying mechanism (2) and a second conveying mechanism (3) which are installed on the first support frame; and a switching mechanism (4) configured to selectively lift the first conveying mechanism or the second conveying mechanism in a vertical direction, such that the first conveying mechanism or the second conveying mechanism carries goods (401) and conveys the goods in a first horizontal direction or a second horizontal direction different from the first horizontal direction. The conveying device may achieve a positioning and a smooth continuous conveying of goods, and achieve a smooth conveying and a calibrated positioning of the goods in different postures.

Abstract: Aspects of the subject technology relate to determining a holdup measurement based on a gamma spectrum through machine learning. A spectral image based on a gamma spectrum generated downhole in a wellbore can be accessed. A component of a holdup measurement for the wellbore can be classified into a specific quantized level through application of a machine learning classification model to the spectral image. A continuous value for the component of the holdup measurement for the wellbore can be quantified by applying a machine learning quantization model associated with the quantized level.

Abstract: A neutron generator with an ion source within a housing may be used for generating neutrons for neutron logging downhole in a wellbore. The ion source within the housing of the neutron generator may include a hot cathode, an ion source cylinder, a first grid separated from the ion source cylinder, and an extractor separated from the ion source cylinder, the extractor having a second grid.

Abstract: A downhole neutron generator includes a housing, a gas reservoir positionable within the housing, a target rod positionable within the housing and having a longitudinal axis aligned with a central axis of the housing, an ion source positionable adjacent to the gas reservoir and between the target rod and the gas reservoir, and a target positionable on a surface of the target rod facing the ion source. The target includes a first metal layer on the surface of the target rod and a second metal layer positionable adjacent to the first metal layer facing the ion source. The second metal layer is a scandium layer.

Abstract: A method and system for identifying one or more petrophysical properties in a formation. The method and system may include disposing a pulsed-neutron logging tool into a borehole that is disposed in a formation, emitting a neutron from a neutron source on the pulsed-neutron logging tool into the formation, and capturing one or more gammas expelled from formation in response to the neutron from the neutron source to form a plurality of pulsed neutron logging (PNL) measurements in a log. The method and system may further include comparing the log to a database with a cost function to form a solution; and identifying a plurality of petrophysical properties based at least in part on the solution.