| 摘要 |
Systems and methods for estimating absolute elemental concentrations of a subterranean formation from neutron-induced gamma-ray spectroscopy are provided. 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. |
