Patent ID: 8427145

Claim:
A method for use in conjunction with a laboratory apparatus defining a sample volume, the method comprising: for a sample collected from a given subsurface formation, storing corresponding downhole tool data that includes parameters pertaining to nuclear magnetic resonance (NMR) measurements of the given subsurface formation performed by a downhole tool, wherein the NMR measurements performed by the downhole tool employ fixed field gradients that have constant amplitude at all times; positioning the sample in the sample volume; performing at least one NMR measurement of the sample volume to thereby determine a property of the sample, the at least one NMR measurement applying to the sample volume a homogeneous static magnetic field in conjunction with a pulse sequence of oscillating magnetic field and a pulsed-mode gradient field, the pulsed-mode gradient field defined by the stored downhole tool data corresponding to the sample, wherein the pulsed-mode gradient field for a given NMR measurement is defined by a set of pulses that are equivalent to the fixed field gradient for a corresponding NMR measurement performed by the downhole tool; and selecting at least one parameter that defines the set of pulses such that the integral of the time-varying amplitude of the pulses of the set over the time duration of the pulses of the set matches the product of the constant amplitude of the fixed field gradient and duration for the corresponding NMR measurement performed by the downhole tool.