Baker Hughes Corporation

Loren Patrick Roberts

Feyzi Inanc

Margarete M Kopal

Anton Nikitin

Alexandr A Vinokurov

Nikolay N Velker

An apparatus and method for estimating at least one parameter of interest of an earth formation including an estimation of the parameter of interest using a time-dependent ratio of information obtained from at least one neutron detector through the exposure of the earth formation to a radiation source, particularly a pulsed nuclear source. The apparatus includes a processor and storage subsystem with a program that, when executed, implements the method. Also, an apparatus and method for estimating at least one parameter of interest of an earth formation including an estimation of the parameter of interest using a first component and a second component of an information set obtained using a single radiation detector.

Time dependent neutron-gamma spectroscopy

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: Z/A, bulk density, Z*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.

Lithology pair ratio: a ratio-based lithology indicator using pair production

An apparatus for estimating porosities of a formation includes: a borehole conveyable pulsed neutron generator to emit a pulse of high energy neutrons; a short spaced neutron detector to provide a count rate as a function of time; a long spaced neutron detector to provide a count rate as a function of time; a timing gate to synchronize a timing of neutrons detected by the detectors with respect to the neutron pulse; and a processor. The processor is configured to determine epithermal count rates and thermal count rates for the detectors based on timing of detection of neutrons with respect to the neutron pulse and calculate a first ratio of short to long spaced detector epithermal count rates and a second ratio of short to long spaced detector thermal count rates. The processor estimates an epithermal porosity using the first ratio and a thermal porosity using the second ratio.

Measuring total, epithermal and thermal neutron formation porosities with one single set of neutron detectors and a pulsed neutron generator

A scintillation detector includes: a photodetector; a scintillating material configured to emit light in response to exposure to ionization particles; an optically transparent material having a light absorption coefficient that is less than a light absorption coefficient of the scintillating material, the optically transparent material optically coupled to a surface of the scintillating material and configured to transmit the emitted light; and a reflective material at least partially surrounding the scintillating material and the optically transparent material, the reflective material configured to reflect the emitted light and direct the emitted light toward the photodetector.

Apparatuses and methods for detection of radiation including neutrons and gamma rays

Time dependent measurement of formation properties using pulsed neutron generators

The present disclosure relates to borehole logging methods and apparatuses for estimating formation properties using nuclear radiation, particularly an apparatus and method for estimating bulk density of a formation. The method may include using gamma ray count rate information to model bulk density. 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.

Apparatus and algorithm for measuring formation bulk density

An apparatus for performing an operation in a borehole penetrating the earth includes a carrier and a neutron source that emits neutrons and is disposed in the carrier. The apparatus also includes a target disposed in the carrier and that produces gamma rays as a result of interactions between neutrons produced by the neutron source and at least one material forming the target. The apparatus also includes a gamma ray detector that detects the gamma rays produced by the target and is disposed in the carrier.

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Humble, TX, United States of America

Loren Patrick Roberts