Xenon NMR Measurements of Permeability and Tortuosity in Reservoir Rocks

TL;DR

This study uses NMR/MRI techniques with xenon gas to measure permeability, porosity, and tortuosity in reservoir rocks, revealing inverse relationships that could improve understanding of rock properties.

Contribution

It introduces a novel application of NMR/MRI with laser-polarized xenon to simultaneously measure permeability, porosity, and tortuosity in rock samples.

Findings

Inverse correlation between tortuosity and permeability

Inverse correlation between tortuosity and effective porosity

Potential for improved understanding of rock permeability-tortuosity relationship

Abstract

In this work we present measurements of permeability, effective porosity and tortuosity on a variety of rock samples using NMR/MRI of thermal and laser-polarized gas. Permeability and effective porosity are measured simultaneously using MRI to monitor the inflow of laser-polarized xenon into the rock core. Tortuosity is determined from measurements of the time-dependent diffusion coefficient using thermal xenon in sealed samples. The initial results from a limited number of rocks indicate inverse correlations between tortuosity and both effective porosity and permeability. Further studies to widen the number of types of rocks studied may eventually aid in explaining the poorly understood connection between permeability and tortuosity of rock cores.