X-ray downhole tool with at least two targets and at least one measurement detector

    公开(公告)号:US12055674B2

    公开(公告)日:2024-08-06

    申请号:US17120788

    申请日:2020-12-14

    IPC分类号: G01V5/12 G01V5/08

    CPC分类号: G01V5/125 G01V5/08

    摘要: 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.

    High voltage supply for compact radiation generator

    公开(公告)号:US11189389B2

    公开(公告)日:2021-11-30

    申请号:US16692121

    申请日:2019-11-22

    摘要: Disclosed is a radiation logging tool, comprising a tool housing; a compact generator that produces radiation; a power supply coupled to the compact generator; and control circuitry. Embodiments of the compact generator comprise a generator vacuum tube comprising a source generating charged particles, and a target onto which the charged particles are directed; and a high voltage supply comprising a high voltage multiplier ladder located laterally adjacent to the generator vacuum tube. The high voltage supply applies a high voltage between the source and the target to accelerate the charged particles to a predetermined energy level. The compact generator also includes an electrical coupling between an output of the high voltage supply and the target of the generator vacuum tube to accommodate the collocated positions of the generator vacuum tube and the high voltage power supply.

    Cement evaluation using neutron tool

    公开(公告)号:US10690802B2

    公开(公告)日:2020-06-23

    申请号:US15658654

    申请日:2017-07-25

    摘要: A method for evaluating cement in a cased wellbore in a geological formation includes placing a downhole tool into the cased wellbore, where the cased wellbore has been cased using a cement that contains a particular material. The method includes emitting neutrons using the downhole tool, wherein the neutrons interact with the particular material via inelastic scattering or capture of neutrons and cause the material to emit an energy spectrum of the gamma rays associated with the material or wherein the time-based measurement of gamma rays or neutrons is influenced by the presence of the material. The method includes using the downhole tool to detect radiation radiation, such as the energy spectrum of the gamma rays, or a die-away pattern of the gamma rays or neutrons that indicates a presence of the particular material and enable to estimate a parameter of the cement.

    FORMATION IMAGING USING NEUTRON ACTIVATION
    4.
    发明申请

    公开(公告)号:US20200183045A1

    公开(公告)日:2020-06-11

    申请号:US16792504

    申请日:2020-02-17

    发明人: Christian Stoller

    IPC分类号: G01V5/10

    摘要: A method for determining azimuthal formation information using neutron activation, wherein the formation is activated by a neutron source and the activation signal is measured by at least one detector trailing the neutron source during the logging operation. The number of detected gamma rays as a function of the detector azimuth may be used to provide azimuthal information for determining an image of the formation surrounding the borehole.

    Systems and methods for monitoring radiation in well logging

    公开(公告)号:US10663617B2

    公开(公告)日:2020-05-26

    申请号:US15393805

    申请日:2016-12-29

    摘要: A downhole tool includes a radiation generator configured to output radiation using electrical power received from a power supply. A first portion of the radiation is emitted into a surrounding sub-surface formation. The downhole tool also includes a radiation detector coupled proximate the radiation generator. The radiation detector includes a micromesh gaseous detector, and the radiation detector is configured to output a measurement signal based at least in part on interaction between a second portion of the radiation output by the radiation generator and the radiation detector. Additionally, the downhole tool includes a control system communicatively coupled to the radiation generator and the radiation detector. The control system is configured to determine measured characteristics of the radiation output from the radiation generator based at least in part on the measurement signal and to control operation of the radiation generator based at least in part on the measured characteristics.

    HIGH VOLTAGE SUPPLY FOR COMPACT RADIATION GENERATOR

    公开(公告)号:US20200098485A1

    公开(公告)日:2020-03-26

    申请号:US16692121

    申请日:2019-11-22

    IPC分类号: G21G4/02 H05H3/06

    摘要: Disclosed is a radiation logging tool, comprising a tool housing; a compact generator that produces radiation; a power supply coupled to the compact generator; and control circuitry. Embodiments of the compact generator comprise a generator vacuum tube comprising a source generating charged particles, and a target onto which the charged particles are directed; and a high voltage supply comprising a high voltage multiplier ladder located laterally adjacent to the generator vacuum tube. The high voltage supply applies a high voltage between the source and the target to accelerate the charged particles to a predetermined energy level. The compact generator also includes an electrical coupling between an output of the high voltage supply and the target of the generator vacuum tube to accommodate the collocated positions of the generator vacuum tube and the high voltage power supply.

    Method for using neutron interaction cross section to interpret neutron measurements

    公开(公告)号:US10466383B2

    公开(公告)日:2019-11-05

    申请号:US14726050

    申请日:2015-05-29

    IPC分类号: G01V5/10 G01N33/24

    摘要: A method for determining a fractional volume of at least one component of a formation includes entering into a computer a number of detected radiation events resulting from imparting neutrons into the formation at an energy level of at least 1 million electron volts (MeV). The detected radiation events correspond to at least one of an energy level of the imparted neutrons and thermal or epithermal energy neutrons. A measurement of at least one additional petrophysical parameter of the formation is made. The at least one additional petrophysical parameter measurement and at least one of a fast neutron cross-section and a thermal neutron cross-section determined from the detected radiation events are used in the computer to determine the fractional volume of the at least one component of the formation. In another embodiment, the fast neutron cross-section and the thermal neutron cross-section may be used on combination to determine the fractional volume.

    Rugged semiconductor radiation detector

    公开(公告)号:US10408969B2

    公开(公告)日:2019-09-10

    申请号:US16163888

    申请日:2018-10-18

    IPC分类号: G01V5/10 G01T1/24 G01V5/08

    摘要: Devices and methods for a rugged semiconductor radiation detector are provided. The semiconductor detector may include a hermetically sealed housing and a semiconductor disposed within the housing that has a first surface and a second surface opposite one another. A first metallization layer may at least partially cover the first surface of the semiconductor and a second metallization layer may at least partially cover the second surface of the semiconductor. The first metallization layer or the second metallization layer, or both, do not extend completely to an edge of the semiconductor, thereby providing a nonconductive buffer zone. This reduces electrical field stresses that occur when a voltage potential is applied between the first metallization layer and the second metallization layer and reduces a likelihood of electrical failure (e.g., due to arcing).

    Method and system for correcting a natural gamma-ray measurement performed in a wellbore

    公开(公告)号:US10317568B2

    公开(公告)日:2019-06-11

    申请号:US15182686

    申请日:2016-06-15

    IPC分类号: G01V5/10 G01V13/00 G01V5/06

    摘要: The disclosure relates to a method for correcting a downhole natural gamma-ray measurement performed in a wellbore. A gamma-ray measurement including at least a gamma-ray count rate is obtained by a gamma-ray detector disposed in a bottom hole assembly having a mud channel inside of the assembly, such that mud flows downwards in the mud channel and upwards outside of the assembly and a neutron source situated above the gamma-ray detector and activating the mud. The method includes: Determining from the gamma-ray measurement an interval count rate corresponding to a count rate of gamma-rays having an energy within a predetermined correction interval; Computing an outside and an inside calibration ratio (ratio of a gamma ray count rate in the correction interval to a gamma-ray count rate outside of the correction interval) representative of gamma-rays generated by an activation of mud flowing respectively outside of the assembly and inside of the assembly, Based on the outside calibration ratio and the interval count rate, determining a first correction count rate, Based on at least the inside and the outside calibration ratios, determining a second correction count rate, Subtracting from the total count rate the first and second correction count rates in order to get a natural gamma-ray measurement corrected for mud activation.