FIELD: physics.
SUBSTANCE: neutron capture gamma-ray spectroscopy system includes: a downhole tool, having: a neutron source configured to emit neutrons into a subterranean formation to cause inelastic scattering events and neutron capture events; a neutron monitor configured to detect a count rate of the emitted neutrons; and a gamma-ray detector configured to obtain gamma-ray spectra derived at least in part from inelastic gamma-rays produced by the inelastic scattering events and neutron capture gamma-rays produced by the neutron capture events; and data processing circuitry 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 normalisation of the relative elemental yield to the count rate of the emitted neutrons.
EFFECT: enabling determination of accurate elemental concentration in neutron capture gamma-ray spectroscopy.
32 cl, 6 dwg
