Abstract: Through analysis on an effective detection space of a gamma detector, a one-dimensional equivalent longitudinal contribution coefficient (varying with a distance between a formation and the detector) of a natural gamma-ray flux received by the gamma detector under the condition that the formation and a wellbore are orthogonal is obtained in the effective detection space, and then a corresponding function expression is given by fitting. An integral of a gamma-ray flux received by the detector under the condition of a deviated well is converted into a one-dimensional equivalent integral problem under the condition of a straight well, so as to achieve the fast forward of natural gamma-ray logging of the formation under the conditions of highly-deviated and horizontal wells. This simplified fast forward algorithm can replace a gamma forward method of spherical spatial-division integrals in parallel sedimentary formations, reduce a space-time complexity of algorithms, and improve a calculation efficiency.

Abstract: Provided herein is a system and method designed for measuring and recording, in three-dimensional space, an attenuation of cosmic-ray induced muon particle flux through a material. The attenuation of the said muons determines density variations in the said material in terms of their density, depth, shape and size. The muon data may be combined with various other data types. The passing muons are detected and recorded by one or a plurality of muon detection apparatus designed to be robust and shock resistant. If needed, each individual muon detection apparatus may be controlled remotely or automatically. The muon detection system may be powered by an energy storage device that may be recharged using renewable energy, aggregate or electric grid. The invention comprises methods steps allowing density characterisation of the material in various dimensions, including those over time.

Abstract: A method of detecting and/or identifying a material or article in a volume of interest, comprises: a) detecting, with an input hodoscope, charged particles entering the volume of interest, b) detecting, with an output hodoscope, charged particles leaving the volume of interest, c) associating particles leaving the volume of interest with particles entering the volume of interest and determining therefrom a set of completed trajectories for the particles, d) performing filtering based on the deflections of the particles with completed trajectories, e) calculating a volume density map based on the filtered completed trajectories which passed through each respective voxel, the map representing a number of completed trajectories and/or a total scattering angle; and f) detecting and/or identifying the material or article in the volume of interest from the volume density map.

Abstract: 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.

Abstract: 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.

Abstract: A system, method, and apparatus for wellbore inspection comprise an electron accelerator to generate X-rays, a rotating collimator assembly configured to produce a cone of X-rays, and at least one detector assembly configured to collect backscattered X-rays. A position assembly can be provided to move the electron accelerator, rotating collimator assembly, and detector through a wellbore. A computer system is configured to receive data from the detector and generate an image of the wellbore.

Abstract: A muon detector system capable of determining muon direction and flight trajectory or path is disclosed. The muon detector system includes scintillators for determining muon direction, and an array of muon detectors arranged in orthogonal layers for determining flight trajectory. The system can be used for tomographic and telescopic mode imaging, and may be used for imaging concealed and/or subterranean objects.

Abstract: A wellbore survey tool and methods for estimating a direction of highest gamma ray intensity of a gamma ray distribution are provided. The tool includes a body having a center axis. The body is configured to be placed within a wellbore. The tool further includes a plurality of gamma ray detectors within the body. Each detector of the plurality of gamma ray detectors has a direction of maximum gamma ray sensitivity with the direction having a non-zero component perpendicular to the center axis. The non-zero components of the plurality of gamma ray detectors are spaced circumferentially about the center axis.

Abstract: A method for determining at least one characteristic of a geological formation having a borehole therein may include collecting nuclear magnetic resonance (NMR) data of the geological formation adjacent the borehole, and collecting non-NMR data for the geological formation adjacent the wellbore. The method may further include performing a Monte Carlo analysis based upon a combination of the collected NMR and non-NMR data to determine the at least one characteristic of the geological formation having a bounded uncertainty associated therewith.

Abstract: A method for simulating a response of a neutron well logging instrument includes in a computer, defining a function of neutron migration length with respect to expected radiation detector counting rate. The function is defined for selected values of formation porosity. The function is related to neutron slowing down length and neutron diffusion length. The function is weighted for formation density. An expected radiation detector counting rate is calculated in the computer using the defined function based on an initial estimation of formation porosity and density.

Abstract: Methods, systems, and computer program products for identifying annular space materials calculate a near-to-far (“N/F”) neutron count ratio from neutron count rates detected by detectors located near to and far from a neutron source, respectively. The N/F neutron count ratio may then be used along with formation porosity to provide an estimation of the type of material that may be present in the annular space.

Abstract: A wellbore survey tool and methods for estimating a direction of highest gamma ray intensity of a gamma ray distribution are provided. The tool includes a body having a center axis. The body is configured to be placed within a wellbore. The tool further includes a plurality of gamma ray detectors within the body. Each detector of the plurality of gamma ray detectors has a direction of maximum gamma ray sensitivity with the direction having a non-zero component perpendicular to the center axis. The non-zero components of the plurality of gamma ray detectors are spaced circumferentially about the center axis.

Abstract: Provided in some embodiments are systems and methods for monitoring cement quality of a cased well. Embodiments include conducting a cement-bond logging and a first pulsed neutron (PN) logging to generate a cement-bond log (CBL) and first pulsed neutron log (PNL) for the well, determining a first cement quality index (CQI) for the well based on the CBL and the first PNL, in response to determining that mud effects for the well have dissipated, conducting a second PN logging to generate a second PNL for the well, determining a second CQI for the well based on the CBL and the second PNL, determining a tuned CQI for the well based on the first CQI and the second CQI, conducting a follow-up PN logging to generate a follow-up PNL for the well, and determining a cement quality log for the well based on the tuned CQI and the follow-up PNL.

Abstract: A method, in some embodiments, comprises lowering a neutron wireline tool into a cased borehole containing casing fluid, determining a ratio of inelastic count rate to capture count rate using gammas passing through the casing fluid, and calculating a capture cross section of the casing fluid using the ratio.

Abstract: Digital mobile communications devices and methods for processing, modulation and demodulation, transmission and reception of spread spectrum signals, Orthogonal Frequency Division Multiplexed (OFDM) signals and conversion of spread spectrum signals into OFDM signals. Received spread spectrum signals from 3G cellular systems are converted into OFDM signals and transmitted in a Wi-Fi network. Received OFDM signals, received in a cellular system in a first RF frequency band, are demodulated and in a repeater mode are re-transmitted in a cellular system in a second OFDM radio frequency band. One or more receivers and demodulators for receiving demodulating and processing received signals into location finder information. A video camera in mobile device generates video signal and transmits video signal with location finder information signal.

Abstract: The present disclosure relates to borehole logging methods and apparatuses for estimating formation properties using nuclear radiation, particularly an apparatus and method for estimating a formation lithology parameter. The method may include using gamma ray count or count rate information to estimate a formation lithology parameter that may be one of, but not limited to: Z2/A, bulk density, Z2*bulk density/A, linear attenuation coefficients, and porosity. The method may include using time-dependent ratios with a pulsed radiation source. The method may also include dividing gamma ray information by time and/or by energy window. The apparatus includes a processor and storage subsystem with a program that, when executed, implements the method.

Abstract: A well-logging device may include a housing to be positioned within a borehole of a subterranean formation, and at least one radiation source carried by the housing to direct radiation into the subterranean formation. The well-logging device may also include noble gas-based radiation detectors carried by the housing in azimuthally spaced relation to detect radiation from the subterranean formation. A controller may determine at least one property of the subterranean formation based upon the detected radiation from the noble gas-based radiation detectors.

Abstract: An apparatus is provided for x-ray inspection of a pipeline girth weld. This comprises a directional x-ray source 5 which is insertable into a pipeline section and is rotatable within the pipeline. Means are provided to align the directional x-ray source with an external x-ray detector such that both may be rotated through 360 degrees substantially coaxially with the pipeline section. Means for sampling the data detected by the x-ray detector are provided so that it may be further analyzed.

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: 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: Various systems and methods for implementing a directional radiation detection tool are disclosed. One such method involves receiving outputs from several radiation sensors (e.g., gamma ray sensors), which are each facing a different direction. The received outputs are then combined, such that a directional error in one of the outputs is reduced, based upon another one of the outputs.

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: The present disclosure relates to determining the attenuation of an electromagnetic signal passing through a conductive material. An antenna is provided and placed in relatively close proximity to the conductive material. An alternating current is passed through the antenna and the impedance of the antenna is measured. The attenuation is determined using the measured impedance. A single frequency measurement may be made, or multiple measurements using different frequencies may be made. Grouped parameters based on properties of the material and the frequency of the current are used to relate the coil impedance to the attenuation. A current frequency for which the ratio of the antenna's resistive part of the impedance to the angular frequency of the current is substantially insensitive to at least one of the parameters is preferred.

Abstract: Method and apparatus enable direct measurement of at least one flow velocity for one or more phases within a multiphase fluid mixture flowing in a conduit. Some embodiments provide determination of actual individual phase flow rates for three phases (e.g., oil, water and gas) that are distinct from one another within the fluid mixture. A multiphase flowmeter according to embodiments of the invention includes at least two optical sensors spatially distributed along a length of the conduit and designed to detect light interactions with the fluid mixture unique to the phases such that detected time-varying signals can be processed via cross-correlation or an array processing algorithm to provide desired individual phase flow velocity for oil, water and/or gas phases. This flow velocity can be applied to phase fraction measurements, which can be obtained utilizing the same flowmeter or another separate device, to calculate the flow rates for the phases.

Abstract: A method and system for determining a property of a sample of fluid in a borehole. A fluid sample is collected in a downhole tool. While collecting, X-rays are transmitted proximate the fluid from an X-ray source in the tool and an X-ray flux that is a function of a property of the fluid is detected. The detected X-ray flux data is processed to determine the property of the fluid.

Abstract: A detection apparatus (D) for photons or ionizing particles (P) is described, in which a detector system (11) is provided with several detecting units (11a), each including a scintillator (112) connected to a reader surface (111a) on an electronic charge reader (111), the scintillator (112) being arranged to generate cellular charges on the reader surface (111a) when capturing the photons or the ionizing particles (P), there being a collimator (113) arranged, connected to the scintillator (112) opposite the electronic charge reader (111), the collimator (113) being arranged to capture photons or ionizing particles (P?) exhibiting a direction of motion coinciding with a longitudinal axis (A) of the collimator (113), and to reject photons or ionizing particles (P?) exhibiting a direction of motion deviating from the direction of the longitudinal axis (A) of the collimator (113).

Abstract: The present invention provides a device for measuring a mean free path capable of measuring directly the mean free path of a charged particle, a vacuum gauge, and a method for measuring a mean free path. The device for measuring a mean free path according to one embodiment of the invention includes an ion source for generating an ion, a collector (24a) for detecting the number of first charged particles being charged particles having a first flight distance L1 that is a flight distance of zero or more from the ion source, and a collector (24b) for detecting the number of second charged particles having a second flight distance longer than the first flight distance. The control part of the device calculates the mean free path from a ratio between the numbers of the first and second charged particles.

Abstract: Methods and related systems are described for use for making subterranean nuclear measurements. The system can include a plurality of elongated scintillator members each generating optical signals in response to ionizing radiation. Optical detector units can be optically coupled to at least one end of each elongated scintillator member so as to detect optical signals from each elongated scintillator member. The system can be suitable for permanent or semi-permanent deployment downhole. For example, the system can operate for more than six months in a subterranean deployment measuring cosmic radiation. The system can be suited to monitor density changes in subterranean regions of interest, for example, density changes brought about by steam injection as part of a steam assisted gravity drainage operation.

Abstract: A position detection method using one or more one-dimensional image sensors for detecting a light source (22) in free space is adapted for use as a portable free-space data input device (20) for controlling of a cursor (42) on the display (44) of a computer. A user of the portable free-space data input device (20) should move the portable free-space data input device (20) in free space to control the movement of the cursor on the display. This portable free-space data input device (20) can also be used as a free-space handwriting device. It is possible to adapt this pointing device in a design of a user-friendly remote control for a multimedia home entertainment system.

Abstract: Method and apparatus enable direct measurement of at least one flow velocity for one or more phases within a multiphase fluid mixture flowing in a conduit. Some embodiments provide determination of actual individual phase flow rates for three phases (e.g., oil, water and gas) that are distinct from one another within the fluid mixture. A multiphase flowmeter according to embodiments of the invention includes at least two optical sensors spatially distributed along a length of the conduit and designed to detect light interactions with the fluid mixture unique to the phases such that detected time-varying signals can be processed via cross-correlation or an array processing algorithm to provide desired individual phase flow velocity for oil, water and/or gas phases. This flow velocity can be applied to phase fraction measurements, which can be obtained utilizing the same flowmeter or another separate device, to calculate the flow rates for the phases.

Abstract: The present invention relates to a well type neutron counter containing a He-3 detector which includes at least one annular gas layer in a polyethylene moderator, which includes a body formed of a neutron moderator and having a sample cavity for inserting a sample of nuclear material therein; and an annular He-3 detector tube including at least one annular gas layer into which at least He-4 or He-3 gas or their mixture is injected and a plurality of anode rods stood in the annular gas layer with an equal spaces, wherein the He-3 detector tube is formed in an inside of the body so as to surround the sample cavity. The neutron counter has a largely reduced size, simplified structure and resultant decreased failure rate as compared to a conventional counter with a large volume.

Abstract: A method of compensating a density log comprises the step of compensating the far density by adding a correction at a given point in the density log wherein: (a) the correction comprises at least a first correction function and optionally a second correction function; (b) when the correction includes both the first and second correction functions they respectively are corrections for “slow-moving” and “fast-moving” perturbations at the said given point; and (c) regardless of whether the correction includes the second correction function the first correction is filtered by a long filter.

Abstract: A method for determining at least one formation property calculated from neutron measurements acquired with a downhole tool includes emitting neutrons from a source in the tool into the formation, detecting neutrons with at least one detector in the downhole tool, calculating a first slowing-down length (L1) based on the detected neutrons, and deriving a second slowing-down length (L2) based on the first slowing-down length (L1). Further steps include deriving a correlation function for relating slowing-down lengths from a first tool to slowing-down lengths associated with a different source, wherein the correlation function depends on formation properties such as bulk density; and applying the correlation function to the slowing-down length of the first tool to derive the slowing-down length of the second tool.

Abstract: Disclosed are a system and method configured for detecting cosmic ray muon (CRM) flux along a variety of trajectories through a subterranean test region, collecting the muon detection data, and processing the data to form a three-dimensional density distribution image corresponding to the test region. In at least one embodiment, the system may be used for identifying concentrations of higher (or lower) density mineral deposits or other geological structures or formations well below the earth's (or ocean floor) surface. The system may be utilized for imaging geological materials and structures of higher and/or lower density in a test region having a depth of several kilometers or more.

Abstract: An apparatus for detecting particles, comprising a plurality of electrically conductive structures disposed on a support element. The structures are electrically insulated from one another and each structure can be electrically connected to an electronic read-out device. The structures receive a beam of particles in a direction forming an angle of incidence with the support element. A trough is disposed between each two successive structures as viewed in the beam direction. And at least partial overlap exists between each two successive structures. The apparatus can be disposed in the focal plane of a mass spectrometer.

Abstract: Disclosed are a system configured for detecting cosmic ray muon (CRM) flux along a variety of trajectories through a subterranean test region, collecting the muon detection data and processing the data to form a three-dimensional density distribution image corresponding to the test region. The system may be used for identifying concentrations of high (or low) density mineral deposits or other geological structures or formations well below the earth's (or ocean floor) surface. The system may be utilized for imaging geological materials and structures of higher and/or lower density in a test region having a depth of several kilometers or more.

Abstract: A method for measuring radiation, the method includes selecting at least two radiation detectors, each detector having a spatial resolution that differs from the spatial resolution of other detectors; measuring the radiation with the detectors; and combining a response from at least two of the detectors to produce a composite response exhibiting a spatial resolution.

Abstract: A logging-while-drilling density sensor includes a gamma ray source and at least two NaI detectors spaced apart from the source for determining measurements indicative of the formation density. A magnetometer on the drill collar measures the relative azimuth of the NaI detectors. Measurements made by the detectors are partitioned into bins defined by azimuth. A compensated bulk density is determined for selected ones of said azimuthal sectors that meet a threshold test related to a minimum difference of measurements or a minimum correction. The method of the invention may also be used with neutron porosity logging devices.

Abstract: Disclosed are a system and method configured for detecting cosmic ray muon (CRM) flux along a variety of trajectories through a subterranean test region, collecting the muon detection data, and processing the data to form a three-dimensional density distribution image corresponding to the test region. In at least one embodiment, the system may be used for identifying concentrations of higher (or lower) density mineral deposits or other geological structures or formations well below the earth's (or ocean floor) surface. The system may be utilized for imaging geological materials and structures of higher and/or lower density in a test region having a depth of several kilometers or more.

Abstract: A gas detection method includes carrying out respective neutron and density logs, using neutron and density detectors, along a length of well. The density log is corrected for the dimensions and properties of the well casing. The corrected density log is then combined with the neutron log to compensate for regions of artificially high density outside the casing. The compensated density log is continuously calibrated against the neutron log. The dynamically calibrated density and neutron logs are inspected for crossovers that signify the presence of gas in a formation.

Abstract: A gamma ray detector assembly for placement in a logging tool in a borehole can include a first gamma ray detector elongated along an axis and having a void extending along the axis. A second gamma ray detector conforms to at least a portion of the void. The first and the second gamma ray detectors are configured to be positioned in the borehole.

Abstract: A pulsed neutron source is used in a density logging tool with three or more detectors. This enables compensation for source variations and provides redundant measurements that are used to make borehole corrections and/or corrections for casing.

Abstract: Measurements made with porosity and density logging tools in a gas reservoir may differ due to invasion effects. The effects are particularly large on measurement-while-drilling applications where invasion is minimal. Using a Monte-Carlo method, a relationship is established between true formation porosity and porosity estimates from density and porosity tools. This relationship is used on real data to get an improved estimate of formation porosity and of gas saturation.

Abstract: A method for determining the diameter of a wellbore, the wellbore being drilled by a drill string immersed in weighted mud, the weighted mud having a significant weight fraction of a heavy component. A well logging instrument having a gamma ray source and energy-sensitive gamma ray detectors rotates within the wellbore to define a transient interface with a facing portion of the wellbore wall. The instrument measures Compton-effect gamma ray scattering and photoelectric-effect gamma ray scattering of gamma rays that cross a first interface, and of later gamma rays that cross an opposite interface, at each of a plurality of locations along the wellbore to produce a group of gamma ray counts at each of a series of wellbore locations. The counts are used to determine standoffs, weight fraction, and wellbore diameter.

Abstract: A wellbore tool for measuring the density of a fluid flowing in a wellbore by a photon attenuation technique includes a tube defining a flow path for the fluid, a photon source at one end of the tube, and a photon detector arranged to receive photons which have passed along the tube. In a preffered implementation, a source which emits coincident photon pairs, preferably 22Na, is used. In this embodiment, the tube defining the fluid flow path has first and second relatively straight and aligned measurement portions disposed on opposite sides of the photon source, so that each measurement portion receives a respective photon of some of the coincident pairs for transmission longitudinally along it. Respective detectors at the other ends of the measurement portions receive respective ones of the photon pairs. The detected coincident photons are counted, and the density of the fluid is derived from the count rate.

Abstract: A logging system for measuring parameters of earth formation penetrated by a well borehole. Measurements made with the system are not adversely affected by varying pressure encountered a borehole environment. This is accomplished by the use of a main compensation element and a detector compensation element to render source and detector geometry invariant to varying pressure. The system is particularly suited for nuclear LWD systems such as back scatter gamma ray density systems. The basic concepts of the system are, however, applicable to other types of nuclear measurement systems that comprise one or more radiation sources, and one or more axially spaced radiation detectors, where system response is a function of source-detector spacing. The basic concepts of the system are also applicable to other types of logging systems, such as electromagnetic and acoustic, where source (transmitter) and sensor (receiver) elements require invariant geometry in order to maximize accuracy of measurements.

Abstract: A logging-while-drilling density sensor includes a gamma ray source and at least two NaI detectors spaced apart from the source for determining measurements indicative of the formation density. An acoustic caliper is used for making standoff measurements of the NaI detectors. Measurements made by the detectors are partitioned into standoff bins. An adaptive spine and rib method uses the standoff measurements to obtain density estimates. The method of the invention may also be used with neutron porosity logging devices.

Abstract: A solid-state image pickup device comprising a semiconductor substrate, and a plurality of photoelectric conversion elements arranged on a surface of said semiconductor substrate both in a line direction and in a column direction perpendicular to the line direction to form a tetragonal lattice, wherein: said photoelectric conversion elements include a plurality of high-sensitive photoelectric conversion elements for performing photoelectric conversion in relatively high sensitivity, and a plurality of low-sensitive photoelectric conversion elements for performing photoelectric conversion in relatively low sensitivity; and said plurality of high-sensitive photoelectric conversion elements and said plurality of low-sensitive photoelectric conversion elements are arranged so as to be shaped like a checkered pattern.

Abstract: A gamma ray detector assembly for placement in a logging tool in a borehole can include a first gamma ray detector elongated along an axis and having a void extending along the axis. A second gamma ray detector conforms to at least a portion of the void. The first and the second gamma ray detectors are configured to be positioned in the borehole.

Abstract: A well logging tool has a neutron source for irradiating formation surrounding a borehole. Two detectors are mounted in a spaced-apart vertical relationship within the tool pressure-resistant housing. Each detector detects capture gamma radiation across the entire gamma ray energy spectrum, windows are set in this spectrum to separate two distinct energy ranges, thereby generating a total of four independent sets of signals, two for each detector. One set of signals is indicative of the hydrogen content and insensitive to the chlorine content of the irradiated formation. The second set of signals is indicative of the hydrogen plus the chlorine content of the irradiated formation. By comparing the sets of signals in two proportional energy ranges, the logging tool allows to generate a log that helps determine the presence or absence of hydrocarbon or salt water in the formation.