A Nonparametric Approach for Determining NMR Relaxation Distributions

Nuclear magnetic resonance (NMR) and imaging (MRI) can provide unique information about fluid distributions, flow, transport properties, and morphology within permeable media. The mathematical description of NMR relaxation of fluids in permeable media is one key element used to develop such information. We introduce and evaluate nonparametric regression theory to determine continuous relaxation distribution functions from NMR/MRI experiments. Unlike other methods, ours is based on determining the best estimate of the distribution function from experimental data. Our method is robust and does not require user interventions, so it is particularly valuable for accurately determining fluid distributions from MRI experiments. Such information is essential for determining porosity, permeability, and fluid saturation distributions, as well as permeable media morphologies.