método e sistema para a inversão sigma da captura de nêutrons pulsada

摘要

In some aspects of the invention, a computer-implemented method of obtaining sigma values from pulsed neutron capture decay curve is disclosed. The method can include selecting spectra collected by pulsed neutron instrument disposed down a borehole traversing a rock formation, the spectra including capture interactions and inelastic interactions; and modeling the selected spectra using a nonlinear model to obtain sigma values relating to one or more reservoir properties.