A downhole logging tool includes a radiation generation source operable to emit radiation into a formation surrounding the tool, a radiation detector fixed relative to the radiation generation source and operable to detect backscattered radiation from the formation surrounding the tool, and a sleeve positioned around the radiation detector to shield the radiation detector from a first portion of the backscattered radiation. The sleeve includes at least one aperture for exposing the radiation detector to a second portion of the backscattered radiation, in which the second portion of the backscattered radiation emanates from an inspected region of the formation facing the at least one aperture. A signal measured at the radiation detector corresponds to the inspected region of the formation, and the position of the at least one aperture is changeable with respect to the formation to distinctly inspect different regions of the formation.

A method and system for forming Representative Elemental Length (REL) of well data. The method may comprise inputting log data from a borehole in a formation into an information handling system, identifying an initial length of the REL section and divide the log data into a plurality of REL investigation sections that are of substantially equal length, calculating an average value of a formation property for each of the plurality of REL investigation sections, and selecting a maximum value and a minimum value of the REL investigation sections. The method may further comprise checking the maximum value and the minimum value are stable, deriving the formation property for each of the REL sections as an output, and forming a model of the formation from each of the REL sections. The system may comprise a downhole device, configured to take measurements of a formation, and an information handling system.

The present disclosure belongs to the field of petroleum exploration and development and, in particular, relates to a system and a method for analyzing while-drilling rock fragments in oil and gas field. The system includes a sample preparation mold and a sample scanning apparatus; the mold is configured to quickly batch prepare fragments into scanning ready samples; the apparatus is portable and configured for batch scanning and analyzing the samples, and having the capabilities of anti-vibration, temperature control, dust prevention, and adaptability to a harsh well site environment; the method includes a scanning step where surface images, elements and mineral types of rock can be rapidly quantitatively analyzed, and lithologies thereof can be identified; the method also includes the analysis step in which rock's elastic parameters and target zone of the vertical well are determined, and geosteering and design of staged fracturing of horizontal well can be provided.

The present disclosure belongs to the field of petroleum exploration and development and, in particular, relates to a system and a method for analyzing while-drilling rock fragments in oil and gas field. The system includes a sample preparation mold and a sample scanning apparatus; the mold is configured to quickly batch prepare fragments into scanning ready samples; the apparatus is portable and configured for batch scanning and analyzing the samples, and having the capabilities of anti-vibration, temperature control, dust prevention, and adaptability to a harsh well site environment; the method includes a scanning step where surface images, elements and mineral types of rock can be rapidly quantitatively analyzed, and lithologies thereof can be identified; the method also includes the analysis step in which rock's elastic parameters and target zone of the vertical well are determined, and geosteering and design of staged fracturing of horizontal well can be provided.

Embodiments provide a method for surveying a hydrocarbon reservoir utilizing a reservoir model. The method includes the step of establishing an ensemble of models reflecting attributes of the hydrocarbon reservoir based on the reservoir model in its present state. The method includes the step of updating the reservoir model by utilizing a volumetric density image of the hydrocarbon reservoir. The volumetric density image can be constructed via muon tomography.

A calibrator is positioned on a logging tool at an angular orientation with respect to the logging tool. The calibrator has a radioactive source of gamma radiation distributed inside the calibrator. A first detector count rate is determined based on a detector in the logging tool detecting gamma radiation. One or more of the calibrator and logging tool is rotated by a first number of degrees. A second detector count rate is determined based on the detector in the logging tool detecting gamma radiation. One or more of the calibrator and logging tool is rotated by second number of degrees. A third detector count rate is determined based on the detector in the logging tool detecting gamma radiation. The first, second, and third detector count rates are averaged to determine a calibration gain factor based on the average detector count rate and a known indication of gamma radiation emitted by the calibrator.

The current disclosure is related to a downhole tool that comprises an electronic photon generator and at least one detector. The electronic photon generator comprises a cathode configured to emit electrons, a first target configured to generate photons when struck by the electrons, a second target configured to generate photons when struck by the electrons, and a beam steering device that directs the electrons to a first or second target. The at least one detector is configured to detect at least some of the photons emitted by the first target and at least some of the photons emitted by the second target.

The current disclosure is related to a downhole tool that comprises an electronic photon generator and at least one detector. The electronic photon generator comprises a cathode configured to emit electrons, a first target configured to generate photons when struck by the electrons, a second target configured to generate photons when struck by the electrons, and a beam steering device that directs the electrons to a first or second target. The at least one detector is configured to detect at least some of the photons emitted by the first target and at least some of the photons emitted by the second target.

Systems and methods are disclosed for well logging using radiation detection and/or emission of gamma rays. A method according to the disclosure includes collecting data from the subterranean formation using a nuclear density tool, wherein the nuclear density tool is configured to collect data to form an azimuthal image. The method further includes characterizing a section of the subterranean formation comprising data and images acquired in a high angle wellbore section, a horizontal wellbore section, or a combination thereof. The method additionally includes performing a parallel inversion using apparent densities and volumetric photoelectric factor images to build a formation model, wherein the parallel inversion comprises a high angle workflow that models high angle wellbore sections and a horizontal workflow that models horizontal wellbore sections.

Systems and methods are disclosed for well logging using radiation detection and/or emission of gamma rays. A method according to the disclosure includes collecting data from the subterranean formation using a nuclear density tool, wherein the nuclear density tool is configured to collect data to form an azimuthal image. The method further includes characterizing a section of the subterranean formation comprising data and images acquired in a high angle wellbore section, a horizontal wellbore section, or a combination thereof. The method additionally includes performing a parallel inversion using apparent densities and volumetric photoelectric factor images to build a formation model, wherein the parallel inversion comprises a high angle workflow that models high angle wellbore sections and a horizontal workflow that models horizontal wellbore sections.