Abstract: The necessary detector configuration and mathematical algorithms to implement a lateral (side-viewing) field of view in a gamma detection probe designed for laparoscopic use is disclosed. For this application, the diameter of the probe is limited to 12 mm. A hybrid collimation design, using a combination of both electronic collimation and metallic shielding, allows the probe to detect gamma emissions form 15 KeV-1.0 MeV. In the lower energy range, the 1.52 mm tungsten shielding is sufficient to collimate the primary detector. Two additional detectors are used to provide electronic collimation and depth detection. The upper energy limit of 1.0 MeV is imposed to exclude the possibility of electron-positron pair production which occurs at energies of 1.022 MeV and greater.

Abstract: A method, system, and taggants (tracers) for quantifying zonal flow in a multi-lateral well having a wellbore with a first lateral and second lateral. The technique includes flowing first produced fluid from a formation via the first lateral into production tubing providing a first taggant through a first dosing tubing to the first lateral, and flowing second produced fluid from the formation via the second lateral into the production tubing and providing a second taggant through a second dosing tubing to the second lateral. A produced stream having the first produced fluid and the second produced fluid flows uphole through the production tubing and discharges from the wellbore. The produced stream may be analyzed to measure an amount of the first taggant in the produced stream and an amount of the second taggant in the produced stream.

Abstract: The use of an environmental sensing wireline standoff may improve operations during borehole logging procedures. An environmental sensing wireline standoff may comprise a lower body, an upper body, and a cable insert. The cable insert may further comprise a first segment and a second segment, wherein the cable insert is disposed between the lower body and the upper body, and wherein the cable insert is configurable to clamp directly onto a wireline cable. The environmental sensing wireline standoff may further comprise a sensor package. A method of assembling an environmental sensing wireline standoff may comprise securing a first segment of a cable insert into a lower body, securing a second segment of the cable insert into an upper body, attaching the sensor package to the upper body, and securing the lower body to the upper body.

Abstract: The use of an environmental sensing wireline standoff may improve operations during borehole logging procedures. An environmental sensing wireline standoff may comprise a lower body, an upper body, and a cable insert. The cable insert may further comprise a first segment and a second segment, wherein the cable insert is disposed between the lower body and the upper body, and wherein the cable insert is configurable to clamp directly onto a wireline cable. The environmental sensing wireline standoff may further comprise a sensor package. A method of assembling an environmental sensing wireline standoff may comprise securing a first segment of a cable insert into a lower body, securing a second segment of the cable insert into an upper body, attaching the sensor package to the upper body, and securing the lower body to the upper body.

Abstract: 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.

Abstract: A system for retrieving a source element from a well may include a logging tool made of a first material, a milling tool, and a control device. The logging tool may include a cylindrical housing having a central chamber housing the source element and extending through a portion of the cylindrical housing along a central axis thereof. The logging tool may include a first communication device mounted on the cylindrical housing. The milling tool may include a tubing mounting structure that secures the milling tool to a tubing of the well. The milling tool may include a drill bit head made of a second material, the drill bit head may be configured for milling through the first material. The control device may include a second communication device configured to communicate with the first communication device.

Abstract: The disclosure provides a well integrity monitoring tool for a wellbore, a method, using a nuclear tool and an EM tool, for well integrity monitoring of a wellbore having a multi-pipe configuration, and a well integrity monitoring system. In one example, the method includes: operating a nuclear tool in the wellbore to make a nuclear measurement at a depth of the wellbore, operating an EM tool in the wellbore to make an EM measurement at the depth of the wellbore, determining a plurality of piping properties of the multi-pipe configuration at the depth employing the EM measurement, determining, employing the piping properties, a processed nuclear measurement from the nuclear measurement, and employing the processed nuclear measurement to determine an integrity of a well material at the depth and within an annulus defined by the multi-pipe configuration.

Abstract: Methods, tools, and systems for determining porosity in an earth formation are disclosed. Neutrons are emitted into the formation to induce inelastic scattering gamma rays and thermal capture gamma rays in the formation. The induced gamma rays are detected at a proximal gamma detector and a far gamma detector, which are spaced at different axial distances from the neutron source. A measured proximal-to-far inelastic ratio (a ratio of inelastic scattering gammas detected at the proximal and far detector) and a proximal-to-far thermal capture ratio (a ratio of thermal capture gammas detected at the proximal and far detector) are determined and used to calculate the formation porosity. Techniques are disclosed for removing borehole and casing configuration effects from the measured proximal-to-far thermal capture ratio, leaving only porosity dependence.

Abstract: The invention is directed to apparatus for measuring mass flow-rates of the gas, oil and water phases in a wet gas, comprising the following parts: a differential pressure flow meter, having a throat section, and a gamma ray detector, comprising a gamma ray emitter and a gamma ray receiver that are arranged in such a manner that gamma rays emitted from the gamma ray emitter can pass through the throat section in diametrical direction to reach the gamma ray receiver; wherein a radioactive source in the gamma-ray emitter is a multi-energy radioactive source that can naturally emit at least three energy gamma rays, and a thermostatic device is not used in the gamma ray receiver. The invention further relates to a metering method for measuring mass flow-rates of the gas, oil and water phases in a wet gas, in which the above apparatus is used.

Abstract: A sub adapted for injection into the wellbore and sensing, the sub comprising: (a) an elongated body; (b) an inner bore having multi-material spacers of different radiation transparencies; and (c) an outer wall having recessed portions along an outside diameter, forming circumferential windows configured to align with a radioactive source and sensors and configured to guide a radioactive energy's path into a formation and back to sensor.

Abstract: The present invention relates to a method and apparatus for detecting radioactivity. In particular, but not exclusively, the present invention relates to the detection of radioactivity in a target fluid in a fluid communication passageway using a region of scintillator material (130) to provide light responsive to the presence of radioactive material and at least one silicon photomultiplier (SiPM) (150) for providing an output signal responsive to the light provided by the scintillator material.

Abstract: A method includes emitting, with one or more sensors of a downhole tool disposed in a borehole, an excitation signal. The method also includes detecting, with the one or more sensors, a returned signal resulting from an interaction of the excitation signal with the borehole. The method further includes estimating a noise of the returned signal. The method also includes quantifying a probability that the estimated noise is not a white noise of the borehole. The method further includes identifying drill cuttings in a predetermined location of the borehole based on said quantification.

Abstract: A tomographic imaging apparatus utilizes Compton backscattering to evaluate cement behind the casing. The imaging apparatus includes a slant-hole or pin-hole collimator coupled to a series of detectors in order to count the number of photons that backscatter off from the cement. The number of backscattered photons is proportional to the density of the cement behind the casing. Using the photon count, an image processing unit of the imaging apparatus generates a 2D or 3D tomographic image of the borehole.

Abstract: Systems and methods are provided for distinguishing between elements located at different distances from a radiation detector used in neutron-induced gamma-ray spectroscopy using a Doppler effect. A pulsed neutron generator may emit neutrons out of a downhole tool in a geological formation at an energy level high enough to cause inelastic scattering with nuclei of an element to generate gamma-rays. A gamma-ray detector may detect the energy levels of the gamma-rays, in the reference frame of the detector, and data processing circuitry takes the detected spectrum of gamma-rays and distinguishes spectra of gamma-ray energy levels for nuclei of the element located nearer to or farther from the detector based at least in part on the Doppler shift of the energy levels of respective gamma-rays.

Abstract: A method for cement evaluation may include generating a gamma ray, from a radioactive source, into cement disposed between a casing and a geological formation. Photons reflected from the geological formation and the cement are detected on a gamma detector having a collimator. A detector-to-source distance, a collimator angle, and/or a collimator diameter are set to provide an energy spectra independent of the geological formation. The quality of the cement may be determined based on the energy spectra of the detected photons.

Abstract: Neutron detectors for measuring a neutron yield of a neutron generator may include at least one particle counter disposed in a housing and at least one removable cartridge for receiving at least one collection medium. The at least one removable cartridge configured to be at least partially inserted into the housing to position the collection medium proximate the at least one particle counter. Detector assemblies for evaluating an output of a particle generator may include a housing and a plurality of cartridges that may be selectively received in the housing. Methods of detecting an output of a neutron source include inserting a collection medium into a cartridge, positioning the collection medium proximate a neutron source, and inserting the cartridge with the collection medium into a housing of a neutron yield detector.

Abstract: A method for determining a petrophysical property of a formation includes detecting radiation events resulting from imparting neutrons into the formation at an energy level of at least 1 MeV. The petrophysical property is determined from an elastic scattering cross section of the formation. The elastic scattering cross-section related to a number of detected radiation events.

Abstract: A method of estimating chordal holdup values of gas, oil, and water (?G, ?O, ?W) for tomographic imaging of a three-phase flow through a volume, including: providing an X-ray source for irradiating through said volume and X-ray sensors for discriminating between a first and a second radiation bands, conducting first calibration measurements (IGS, IOS, IWS) of said first radiation band, conducting second calibration measurements (IGH, IOH, IWH) of said second radiation band, arranging a mixture of two or more fluids, irradiating said volume and conducting X-ray measurements (IS, IH) in said radiation bands, establishing a relationship between a function of holdup values f(?G, ?W) of at least gas and water and said X-ray measurements (IS, IH), searching holdup values (?G, ?W) that minimize said function of holdup values f(?G, ?W) under the constraints of the sum of said holdup values is more than or equal to zero and less than or equal to one, i.e. that 0??G+?W?1.

Abstract: The present invention relates to a scanning tool (1) for scanning an object downhole. The tool has a longitudinal axis and comprises an emitting device (2) for emitting radiation, a lens (3) for transmitting the radiation in a predetermined pattern (4) of radiation, and a receiving device (5). In a first position of the tool, the pattern of radiation is reflected on the object (6) to be scanned and the reflected radiation is received in the receiving device resulting in a first measurement.

Abstract: Systems and methods are provided for determining a property, e.g., density, of a geological formation based on Einstein's theory of gravitation. A gravitational potential difference is determined between two positions of the geological formation by measuring a frequency shift of a radiation travelling from a source to an absorber of a differential gravimeter. The gravitational potential difference determined can be converted to a density of the geological formation, e.g., based on a concentric spherical shell model. The systems can be a part of a downhole tool.

Abstract: Systems and methods are provided for determining a property, e.g., density, of a geological formation based on Einstein's theory of gravitation. A gravitational potential difference is determined between two positions of the geological formation by measuring a frequency shift of radiation travelling from a source to an absorber of a differential gravimeter. The differential gravimeter can be a part of a downhole tool. The gravitational potential difference determined can be used to determine the property of the geological formation.

Abstract: Determining a value indicative of gas saturation of a formation. At least some of the illustrative embodiments are methods including: obtaining an inelastic count rate and a capture count rate of a gamma detector for a particular borehole depth; removing at least a portion of the chlorine response from the capture count rate, thereby creating a modified capture count rate; calculating a ratio of an inelastic count rate to the modified capture count rate for the particular borehole depth; determining a value indicative of gas saturation based on the ratio; and producing a plot of the value indicative of gas saturation as a function of borehole depth for a formation that the borehole at least partially penetrates.

Abstract: A system and method for use in a downhole tool having a fluid density measurement device positioned therein are provided. In one example, the method includes deploying the downhole tool at a first station in a borehole. The downhole tool is moved from the first station to a second station in the borehole. A plurality of fluid density values of fluid within the borehole between the first and second stations are measured using the fluid density measurement device in the downhole tool. The plurality of fluid density values may represent a continuous log of fluid densities between the first and second stations.

Abstract: Systems and methods are provided for determining a property, e.g., density, of a geological formation based on Einstein's theory of gravitation. A tandem-structured gravimeter uses two gamma radiations emitted to two directions to determine a gravitational potential difference between two positions of the geological formation. The gravimeter can be a part of a downhole tool. The gravitational potential difference determined can be used to determine the property of the geological formation.

Abstract: Well logging method and logging tool for measuring cement density and thickness at different azimuth angles for a cemented, cased well. The method uses a gamma source, a short-spaced detector, a long-spaced detector, and preferably a backscatter detector, where the detector-to-source spacings are designed for calculating (93) thickness and density of the cement annulus (94) from the detector count rates (91).

Abstract: An apparatus for estimating at least one property of an earth formation is disclosed. The apparatus includes: a carrier configured to be disposed in the formation; a neutron tube disposed at the carrier and located on an axis; a high voltage power source disposed in the carrier and electrically connected to the neutron tube, the high voltage power source located remotely from the neutron tube; and at least one detector disposed in the carrier and located proximate to the neutron tube.

Abstract: Methods and related systems are described for gamma-ray detection. A gamma-ray detector is made depending on its properties and how those properties are affected by the data analysis. Desirable properties for a downhole detector include; high temperature operation, reliable/robust packaging, good resolution, high countrate capability, high density, high Z, low radioactive background, low neutron cross-section, high light output, single decay time, efficiency, linearity, size availability, etc. Since no single detector has the optimum of all these properties, a downhole tool design preferably picks the best combination of these in existing detectors, which will optimize the performance of the measurement in the required environment and live with the remaining non-optimum properties.

Abstract: Substances on or adjacent a tubular disposed in a subterranean wellbore can be detected and/or their presence identified by monitoring gamma rays scattered from the substances. The substances include deposits on a sidewall of the tubular and liquid contained in the tubular. Examples of the deposits include asphaltenes, paraffins, scale, sand, and the like. Gamma rays are strategically directed from a tool disposed within the tubular and to adjacent a sidewall of the tubular. Some of the gamma rays scatter from the substances adjacent the tubular and are detected with detectors set a designated axial distance from the gamma ray source.

Abstract: Voids adjacent a wellbore wall and in a region surrounding a wellbore wall can be detected by monitoring gamma rays scattered from the fractures. Gamma rays are strategically directed from a tool disposed within the wellbore and to the wall and/or the region. Some of the gamma rays scatter from the voids and are detected with detectors set a designated axial distance from the gamma ray source. In addition to identifying the presence of the voids, the location and size of the fractures/perforations is also estimated. Time lapsed imaging of the wellbore wall can yield changes in the voids that in turn can affect permeability of the well. Examples of the voids include fractures and/or perforations.

Abstract: This device comprises a single radioactive source (44), capable of creating an incident beam (120), and a target (48) placed opposite the source (44). The target (48) is capable of creating the second beam (130) by interacting with a first part of the incident beam (120), a second part of the incident beam (120) passing through the target (48) to form the first beam (124).

Abstract: A downhole gamma ray density measurement system is described. The gamma ray density measurement system includes a pressure housing and a gamma ray source within the pressure housing. One or more detectors within the pressure housing detect gamma radiation. One or more low-attenuation inserts may be located in the pressure housing near the gamma ray source and/or one or more of the detectors. One or more high-attenuation inserts may be located in the pressure housing near the gamma ray source and/or one or more of the detectors.

Abstract: A nuclear imaging system includes a crystal identification system which receives a flood image which includes a plurality of peaks, each peak responsive to radiation detected by a corresponding scintillator crystal. A crystal identification processor partitions the flood image into a plurality of candidate regions with a watershed segmentator implementing a watershed algorithm. The candidate regions are linked in an adjacency graph, and then classified as background or relevant, where relevant regions contain a peak within the watershed lines. The regions are then assigned to a crystal according to an objective function and an assignability score. A calibration processor maps the peaks to a rectangular grid.

Abstract: A nuclear imaging system (10) includes a crystal identification system (40) which receives a flood image (30) which includes a plurality of peaks, each peak responsive to radiation detected by a corresponding scintillator crystal. A crystal identification processor (42) partitions the flood image (30) into a plurality of regions (56), each region being masked to correspond to one of an array of nuclear detectors. A model image (62) is generated in which the at least one Gaussian models represents the identified peaks. Misidentified peaks in the model image (62) in which locations of the peaks in the flood image (30) differ from the corresponding scintillator crystal are determined and the locations of the misidentified peaks in the flood image (30) are corrected. A calibration processor (43) corrects geometric distortions in acquired projection data according to the corrected peaks.

Abstract: This invention relates to nondestructive control, more specifically, to the detection of cracks, flaws and other defects in oil and gas wells and cementing quality control.

Abstract: A full bore spectral gas holdup tool that measures gas holdup that is corrected for effects of the flowstream lamination and the salinity of the liquid in the a flowstream. The basic methodology utilizes spectral data from two gamma ray detectors at different spacings from a nuclear source that emits gamma radiation. 57Co is the preferred source and the gamma ray detectors are scintillation spectrometers. In addition to a full bore gas holdup measurement, the spectral gas holdup tool also provides indications of the degree of flowstream lamination and the salinity of the liquid in the flowstream. An iterative data processing method optimizes the accuracy of the measured flowstream parameters.

Abstract: Apparatus for wellbore logging and method of use are provided for measurement of the annular materials interposed between the logging tool and formation and the apparent formation bulk density in open-hole, cased-hole or other conduit. The logging tool can be centralized in the borehole. Non-collimated gamma radiation is emitted into the surrounding media and the amount of radiation which returns to the tool is measured by multiple omni-directional detectors spaced a pre-set distances from the source to provide multiple radial depths of investigation. The annular thickness and density of materials interposed between the logging tool and the formation may be determined from the detector responses and be used to derive the apparent formation bulk density.

Abstract: Methods and related systems are described for gamma-ray detection. A gamma-ray detector is made depending on its properties and how those properties are affected by the data analysis. Desirable properties for a downhole detector include; high temperature operation, reliable/robust packaging, good resolution, high countrate capability, high density, high Z, low radioactive background, low neutron cross-section, high light output, single decay time, efficiency, linearity, size availability, etc. Since no single detector has the optimum of all these properties, a downhole tool design preferably picks the best combination of these in existing detectors, which will optimize the performance of the measurement in the required environment and live with the remaining non-optimum properties.

Abstract: In one aspect, the present disclosure provides an apparatus for determining formation density. One embodiment of the apparatus includes a bottomhole assembly having a drill bit attached to end thereof for drilling through a formation, a first sensor in the drill bit configured to provide first signals for determining a first density of the formation proximate to the drill, a second sensor distal from the first sensor configured to provide signals for determining density of a second density of the formation, and a processor configured to determine the formation density from the first density and the second density.

Abstract: Systems and methods are provided for determining a property, e.g., density, of a geological formation based on Einstein's theory of gravitation. A gravitational potential difference is determined between two positions of the geological formation by measuring a frequency shift of radiation travelling from a source to an absorber of a differential gravimeter. The differential gravimeter can be a part of a downhole tool. The gravitational potential difference determined can be used to determine the property of the geological formation.

Abstract: Systems and methods are provided for determining a property, e.g., density, of a geological formation based on Einstein's theory of gravitation. A tandem-structured gravimeter uses two gamma radiations emitted to two directions to determine a gravitational potential difference between two positions of the geological formation. The gravimeter can be a part of a downhole tool. The gravitational potential difference determined can be used to determine the property of the geological formation.

Abstract: Systems and methods are provided for determining a property, e.g., density, of a geological formation based on Einstein's theory of gravitation. A gravitational potential difference is determined between two positions of the geological formation by measuring a frequency shift of a radiation travelling from a source to an absorber of a differential gravimeter. The gravitational potential difference determined can be converted to a density of the geological formation, e.g., based on a concentric spherical shell model. The systems can be a part of a downhole tool.

Abstract: Method and apparatus for real-time tracking of a target in a human body. In one embodiment of the invention, positron emission marker may be implanted into a target, the positron emission marker having a low activity positron isotope. In one embodiment, annihilation gamma rays associated with the low activity positron isotope may be detected using a plurality of position-sensitive detectors. In another embodiment, the target may be tracked in real-time based on a position of the positron emission marker.

Abstract: A method for performing a measurement of a property downhole includes: using an instrument including an irradiator including a pulsed neutron generator, a moderator and a material including a high cross section for capturing thermal neutrons downhole, generating inelastic gamma photons from neutron interactions in the moderator and generating capture gamma photons from neutron interactions in the material; irradiating sub-surface materials proximate to the instrument with the inelastic gamma photons and the capture gamma photons; detecting radiation scattered by the sub-surface materials; and estimating the property according to the detected radiation. A system is also disclosed.

Abstract: Methods and related systems are described for gamma-ray detection. A gamma-ray detector is made depending on its properties and how those properties are affected by the data analysis. Desirable properties for a downhole detector include; high temperature operation, reliable/robust packaging, good resolution, high countrate capability, high density, high Z, low radioactive background, low neutron cross-section, high light output, single decay time, efficiency, linearity, size availability, etc. Since no single detector has the optimum of all these properties, a downhole tool design preferably picks the best combination of these in existing detectors, which will optimize the performance of the measurement in the required environment and live with the remaining non-optimum properties.

Abstract: Nuclear gauges, their components and method for assembly and adjustment of the same are provided. The nuclear gauges are used in measuring the density and/or moisture of construction-related materials. The nuclear gauge can include a gauge housing having a vertical cavity therethrough and at least one radiation detector located within the housing. The nuclear gauge can include a vertically moveable source rod and a radiation source operatively positioned within a distal end of the source rod. The nuclear gauge can also include a radiation shield assembly.

Abstract: Substances on or adjacent a tubular disposed in a subterranean wellbore can be detected and/or their presence identified by monitoring gamma rays scattered from the substances. The substances include deposits on a sidewall of the tubular and liquid contained in the tubular. Examples of the deposits include asphaltenes, paraffins, scale, sand, and the like. Gamma rays are strategically directed from a tool disposed within the tubular and to adjacent a sidewall of the tubular. Some of the gamma rays scatter from the substances adjacent the tubular and are detected with detectors set a designated axial distance from the gamma ray source.

Abstract: The subject matter described herein includes methods, systems, and computer program products for measuring the density of a material. According to one aspect, a material property gauge includes a nuclear density gauge for measuring the density of a material. A radiation source adapted to emit radiation into a material and a radiation detector operable to produce a signal representing the detected radiation. A first material property calculation function may calculate a value associated with the density of the material based upon the signal produced by the radiation detector. The material property gauge includes an electromagnetic moisture property gauge that determines a moisture property of the material. An electromagnetic field generator may generate an electromagnetic field where the electromagnetic field sweeps through one or more frequencies and penetrates into the material.

Abstract: Monitoring scattered gamma rays is used to identify substances disposed between coaxial tubulars disposed in a subterranean wellbore. Gamma rays are strategically directed from within an inner most tubular and into the annulus, some of the gamma rays scatter from the substance between the tubulars and are detected with detectors set a designated axial distance from the gamma ray source. Gamma rays also scatter from fluid within the tubular, a ratio of the gamma rays detected that scatter from the fluid in the tubular and from the substance can be used to determine the substance.

Abstract: An apparatus and method for estimating ore quality using color correlations is disclosed. The apparatus and method quantify ash or grade concentration in process streams arid/or samples in real time, allowing for the optimization of ore processing operations, The apparatus and method employ a light beam at a given wavelength, which allows for the measurement of ash content or grade.

Abstract: A gamma ray detector assembly for a borehole logging system that requires the measure of gamma radiation with optimized gamma ray energy resolution and with fast emission times required to obtain meaningful measurements in high radiation fields. The detector assembly comprises a lanthanum bromide (LaBr3) scintillation crystal and a digital spectrometer that cooperates with the crystal to maximize pulse processing throughput by digital filtering and digital pile-up inspection of the pulses. The detector assembly is capable of digital pulse measurement and digital pile-up inspection with dead-time less than 600 nanoseconds per event. Pulse height can be accurately measured (corrected for pile-up effects) for 2 pulses separated by as little as 150 nanoseconds. Although the invention is applicable to virtually any borehole logging methodology that uses the measure of gamma radiation in harsh borehole conditions, the invention is particularly applicable to carbon/oxygen logging.