32 results about "Gamma ray spectra" patented technology

Apparatus and methods for measuring gamma ray energy spectra wherein the gain of the measurement system is continuously and automatically adjusted to a standard gain. Gain of the system is controlled automatically through analysis of the measured energy spectra. Alternately, the gain of the system is controlled by the use of a calibration source and the operation of the system at a standard and amplified gain. Gain control can be improved further by combining both the spectral analysis and calibration source methodology. The system can be embodied in a wireline or logging-while-drilling borehole logging systems that measure naturally occurring or induced gamma ray spectra. The system can also be used in non-borehole applications including non-borehole gamma ray spectral systems such as computer-aided-tomography scan systems, security scanning systems, radiation monitoring systems, process control systems, analytical measurement systems using activation analysis methodology, and the like.

A method and apparatus are provided for correcting gamma ray data representative of gamma ray energies for spectral degradation. The method and apparatus include degrading reference gamma ray spectra. At least one correction factor is calculated between the degraded gamma ray spectra and the reference gamma ray spectra. The gamma ray data are then corrected using a calculated correction factor. Another method is provided for determining a correction factor for correcting data representative of gamma ray energies for spectral degradation. The method includes disposing a downhole tool in a simulated environment representative of actual downhole conditions, the tool including a neutron source and at least one gamma ray detector. The temperature of at least one of the gamma ray detectors of the tool is then varied while the simulated environment is irradiated with neutrons emitted from the neutron source. Gamma ray energy signals are then detected at the at least one detector in response to gamma rays produced during nuclear reactions between the neutrons and materials in and of the simulated environment. A characteristic of the simulated environment is then determined along with a characteristic of the at least one detector. The determined characteristics of the simulated environment and of the at least one detector are then correlated to determine at least one correction factor.

The present invention discloses a system and method for estimating absolute elemental concentrations of a subterranean formation from neutron-induced gamma-ray spectroscopy. In one example, a system (10) for estimating an absolute yield of an element in a subterranean formation may include a downhole tool (12) and data processing circuitry (14). The downhole tool may include a neutron source (18) to emit neutrons into the formation, a neutron monitor (20) to detect a count rate of the emitted neutrons, and a gamma-ray detector (26,28) to obtain gamma-ray spectra deriving at least in part from inelastic gamma- rays produced by inelastic scattering events and neutron capture gamma-rays produced by neutron capture events. The data processing circuitry may be configured to determine a relative elemental yield from the gamma-ray spectra and to determine an absolute elemental yield based at least in part on a normalization of the relative elemental yield to the count rate of the emitted neutrons.

The invention provides a formation element capture gamma-ray spectra measurement method and device, and belongs to the technical field of oil-gas exploration logging. The method comprises the steps that a neutron source is slowed down according to the neutron capture cross section of samples to be measured; and standard capture gamma-ray spectra of the samples to be measured can be acquired through measurement when thermal neutron flux of reaction of the neutron source through slowing down and the atomic nucleus of the samples to be measured reaches the position of the preset value. The neutron source is slowed down according to the neutron capture cross section of different samples to be measured so that the element capture gamma-ray spectra of the samples to be measured can be acquired through measurement, and multiple types of formation element capture gamma-ray spectra with higher accuracy can be acquired.

The invention provides a method and a device for evaluating abundance of organic matter of a hydrocarbon source rock, wherein the method comprises the following steps: emitting high-energy neutron to a stratum; recording an inelastic scattering gamma-ray spectra generated by the interaction of nucleus of elements in the stratum and the high-energy neutron; analyzing the inelastic scattering gamma-ray spectra, to obtain the content of elements in the stratum; obtaining the content of inorganic carbon in the stratum by using the elements associated with the content of the inorganic carbon; deducting the content of the inorganic carbon from the total carbon content of the stratum, so as to obtain the content of the organic carbon in the stratum; evaluating the abundance of organic matter of the hydrocarbon source rock by using the content of the organic carbon element.

The invention provides a spectrometer for gamma ray imaging, which consists of a uniform redundant array encoding board, a detection module, a front-end signal processing module, an A/D module, a control module, a data interface module, a power supply module, and a lead shielding layer composition. In the lead shielding layer, the uniform redundant array coding board is placed at the front of the detection module; the detection module is connected to the front-end signal processing module through a cable; the A/D module is connected to the front-end signal processing module, and then connected to the control module through a double row of pins The control module is connected to the data interface module through the cable socket; the data interface module is output to the upper PC through Ethernet; the power module processes the input low-voltage DC power of the system and supplies it to each module respectively. The gamma-ray imaging energy spectrometer provided by the invention can be used for both gamma-ray imaging and gamma-ray energy spectrum measurement.

The invention discloses a small-bore gamma-ray spectra well logging device as well as a data acquisition transmission and self-stabilization method. In order to achieve the aim of continuous gamma-ray spectra well logging, the small-bore gamma-ray spectra well logging device is provided. The small-bore gamma-ray spectra well logging device comprises a BGO scintillation crystal probe, a Ba self-stabilization source, a photomultiplier, a first amplifier, a pole zero cancellation circuit, a second amplifier, a base line restoring circuit, a high voltage module, a self-stabilization circuit, a sampling hold circuit, a threshold comparing circuit, an A/D conversion circuit, an address latch, a first microprocessor, a double-port RAM, a second microprocessor and a time-base circuit, so that the data throughput rate is improved; a synchronization mechanism is designed between the two microprocessors to guarantee the completeness of a gamma-ray spectra data frame. The data frame is like an FIFO, and the gamma-ray spectra data frame which is written at first by the microprocessor 1 is taken away from the microprocessor 2 at first; the microprocessor 1 bears high-speed gamma pulse acquisition, functions of data reading, combination processing, automatic spectra stabilization and the like are realized by the microprocessor 2, and the spectra data are sent to a ground system through an asynchronous serial port in real time.

A system for identifying radionuclide emissions is described. The system includes at least one processor for processing output signals from a radionuclide detecting device, at least one training algorithm run by the at least one processor for analyzing data derived from at least one set of known sample data from the output signals, at least one classification algorithm derived from the training algorithm for classifying unknown sample data, wherein the at least one training algorithm analyzes the at least one sample data set to derive at least one rule used by said classification algorithm for identifying at least one radionuclide emission detected by the detecting device.

The invention discloses a rapid ore prospecting method for a shallow coverage region of Gobi and desert areas. The method comprises: step A, selecting a favorable metallogenic area; step B, compilinga surface geological map; step C, compiling high-precision magnetic survey inferring structure explaining map with the scale of 1 to 10000; step D, making a soil measurement anomaly map and an inferential structure explanatory map with the scale of 1 to 10000; step E, making an induced intermediate gradient measurement apparent chargeability contour map, a apparent resistivity contour map, and aninference structural interpretation map with the scale of 1 to 10000; step F, making an undermining gamma-ray spectra measurement uranium, thorium, potassium, general-path contour planar graph and aninference structural interpretation map with the scale of 1 to 10000; step G, making a mining area bedrock geological structure lithologic map; step H, tracing a surface mineralization alteration zone; step I, determining a surface trenching engineering location; step J, determining a theoretical coordinate value of a drilling location; step K, installing a core drilling rig; step L, carrying outwhole-hole core acquisition; and step M, carrying out center alignment sampling analysis to obtain grade and spatial location data. Therefore, mineralization data can be collected comprehensively; thegeological mineralization conditions are studied comprehensively; and the efficiency is improved.

The invention provides a method and device for determining stratum mineral content. The method comprises the following steps: acquiring a hybrid Gamma-ray spectra produced by the nuclear reaction of multi-elements in a to-be-detected stratum with fast neutrons; decomposing the hybrid Gamma-ray spectra to obtain relative yield of each element in the multi-elements in the to-be-detected stratum; computing to obtain the content of each stratum mineral in multiple stratum minerals in the to-be-detected stratum according to the relative yield of the element and a preset quantitative relation, wherein the quantitative relation is the quantitative relation between the relative yield of single element and the content of the stratum mineral containing the single element. The quantitative relation between the relative yield of single element and the content of the stratum mineral containing the single element is established by the method in the embodiment of the invention, thereby directly computing the contents of different stratum minerals in the to-be-detected stratum through the relative yield of the element, the computing precision of the stratum mineral content is effectively improved, and the accuracy of the computation result of the stratum mineral content is guaranteed.

A screen pipe horizontal well production profile testing apparatus and a testing method for the same are provided to overcome defects of difficulty of instrument loading, high testing cost and large construction risk of horizontal production profile testing technology for a screen pipe completion well in the prior art. In the screen casing horizontal well production profile testing apparatus, a releasing device (I), a releasing device (II) and a releasing device (III) are orderly fixedly connected via screen pipes; tracer agent is respectively disposed in the three releasing devices; during well completion practice, the testing apparatus is connected into a well completion pipe string; the releasing device (I) is arranged on a separation layer between a toe production layer and a middle production layer; the releasing device (II) is arranged on a separation layer between the middle production layer and a heel part production layer; the releasing device (III) is arranged on a separation layer on the back part of the heel part production layer; well completion construction is conducted; after the apparatus is put into practice, gamma-ray spectra analysis is conducted to produced liquid via gamma-ray spectra detection equipment on the ground; and production profiles can be analyzed according to types and feature contents of detected tracer agents.

The invention discloses a method for judging sources of fission products in nuclear power plant reactor letdown pipelines. The method comprises steps as follows: the reactor letdown pipelines are detected by a gamma ray detector in real time to obtain fission nuclide characteristic gamma ray spectrums in the reactor letdown pipelines; a signal amplification processing unit receives fission nuclide characteristic gamma ray spectrum signals detected by the gamma ray detector, amplifies and transmits the signals to a supervisory control computer; the supervisory control computer performs spectral analysis on the received fission nuclide characteristic gamma ray spectrums according to the pressure, the temperature and the flow velocity of reactor primary coolant circuit water as well as the reactor power, and determines nuclides in the reactor letdown pipelines according to characteristic gamma rays obtained through the spectral analysis; and the resources of the fission products in the reactor letdown pipelines are judged according to whether long-service-life nuclides with service lives longer than a first set value, short-service-life nuclides with service lives shorter than a second set value or non-volatile nuclides exist in the reactor letdown pipelines.

The invention discloses a method for calculating organic carbon content of a stratum while drilling. The method for calculating the organic carbon content of the stratum while drilling is based on cutting gamma-ray spectra uranium analysis data and cutting experiment analysis organic carbon content data, an interpretation model is built according to the correlation there-between, and the organic carbon content of the stratum is calculated according to the interpretation model while drilling. The method for calculating the organic carbon content of the stratum while drilling realizes to calculate the organic carbon content of the stratum while drilling and solves the problem that the organic carbon content of the stratum calculated through gamma-ray calculation while drilling is imprecise.

A method for estimating an aspect of a formation using a nuclear spectroscopy tool includes placing a nuclear spectroscopy tool into a borehole and emitting neutrons such that some of the neutrons generate gamma rays from a formation adjacent the nuclear spectroscopy tool and some of the neutrons generate gamma rays from elements within the nuclear spectroscopy tool. An energy spectrum of gamma rays induced by the emitted neutrons can be detected. The energy spectrum includes a background having a plurality of measured spectral components. A background ratio between at least one spectral component of the background and another measured spectral component can be determined or estimated in accordance with environmental measurements. The detected gamma ray spectra can be analyzed using a combination of standard spectra and subtracting at least one spectral component of the background in accordance with the background ratio.

The invention discloses a carbon-oxygen ratio calculation method used for determining remaining oil saturation. Firstly, a Gaussian and linear dual model is used for fitting and actually measuring carbon and oxygen energy peaks of inelastic gamma-ray spectrum data, and characteristic peak fitting coefficients are obtained; then, the same fitting model is used for fitting energy peaks corresponding to carbon and oxygen standard gamma-ray spectra; the ratio of height of measurement spectrum carbon peak Gaussian components and height of standard spectrum carbon peak Gaussian components is multiplied by the total number of carbon element standard spectra, so that inelastic gamma-ray generated by a carbon element is counted; the ratio of height of measurement spectrum oxygen peak Gaussian components and height of standard spectrum oxygen peak Gaussian components is multiplied by the total number of oxygen element standard spectra, so that inelastic gamma-ray generated by an oxygen element is counted; the two numbers are divided to generate the carbon-oxygen ratio. The method reduces influences of gamma-ray generated by other elements on the carbon-oxygen ratio, and improves response sensitivity of the carbon-oxygen ratio to oil saturation.

The invention discloses a gamma-ray spectra nuclide detection analysis method used in a biological sample, which comprises the following steps of: (1) after classifying, cleaning, air-drying and weighing the biological sample, carrying out smashing pulping or cutting segmentation processing; (2) carrying out freeze drying on the sample; (3) carrying out grinding smashing on the freeze-dried sample, sieving, calculating a dry-fresh ratio of the biological sample, and obtaining biological freeze-dried powder; (3) carrying out pressing formation on the biological freeze-dried powder by utilizinga die; (4) carrying out vacuum packaging on the sample subjected to pressing formation; and (5) carrying out high-purity germanium or sodium iodide gamma-ray spectra nuclide detection. The gamma-ray spectra nuclide detection analysis method adopts a biological radioactive rapid pretreatment method combining large-volume rapid freeze drying, grinding smashing and die-pressing source making, implements rapid relative measurement of nuclide by a radioactive gamma-ray spectra method, and is beneficial for implementing biological radioactive detection analysis which is simple, rapid, efficient, lowin cost, low in environment pollution, scientific and accurate.

The present invention relates to a nuclear purity quick determination apparatus and method for a radionuclide nuclide iodine-125. The apparatus comprises a sample room, an energy discrimination shielded flask, a multi-channel energy spectrometer and a special lead shielded apparatus. The present invention also comprises an energy discrimination shielded room using high density materials such as lead or iron. The thickness of a lead shielded layer ranges from 0.5mm to 1.0mm. The thickness of an iron shielded layer is 10mm. The multi-channel energy spectrometer adopts a sodium iodide NaI Gamma spectrometer with low energy resolution. The determination method of the present invention comprises steps as follows: (1), the iodine-125 is fully shielded by the energy discrimination shielded flask; (2), nuclide identification and characteristic photon are conducted to iodine-126; (3) the measured result is analyzed using SPAN/Win NaI sodium iodide Gamma ray spectra, so the percentage composition of iodine-126 is measured. The present invention results in that the iodine-125 seed source manufacturing enterprise can use the energy spectrometer with low cost and maintenance requirement and the ray energy discrimination technology to measure the percentage composition of the impurity nuclide with low content quickly and accurately. The present invention is of low investment and convenient routine maintenance.

The present disclosure describes various embodiments related to methods for determining salinity of water in a borehole of a formation and the water in the formation. Various methods may use inelasticand capture gamma-ray spectra obtained from a pulsed neutron logging tool. Various embodiments may use a ratio of chlorine from a capture spectrum to oxygen from an inelastic spectrum for a near anda far detector to calculate apparent salinity ratios for water in a borehole and a formation. From the apparent salinity ratios, a borehole salinity and a formation salinity may be calculated using atool characterization database and without using formation water saturation for the calculation. Other embodiments may be disclosed or claimed.