Nuclear Magnetic Resonance Applications in Porous Media Characterization

Nuclear magnetic resonance (NMR) has emerged as a versatile nondestructive probe of pore structure and fluid behaviour in a wide range of porous materials. By monitoring the relaxation properties of hydrogen nuclei, NMR techniques can resolve porosity, pore-size distributions, permeability and fluid saturations at both laboratory and in situ scales. Low‐field relaxometry provides rapid assessment of pore networks in soils, rocks and engineered composites, while high‐field NMR and magnetic resonance imaging (MRI) yield spatially resolved snapshots of fluid displacement and transport dynamics. Advanced pulse sequences and multi‐dimensional experiments further distinguish bound and free fluids, wettability contrasts and susceptibility‐induced internal gradients. Integration with complementary methods—such as mercury capillary pressure and core flooding—has refined models of pore connectivity and capillary behaviour. Across hydrocarbon recovery, soil science, carbon capture and civil engineering, NMR fosters a deeper mechanistic understanding of multiphase flows in complex porous media, informing reservoir management, contaminant remediation and the design of novel functional materials.

Research from Nature Portfolio

Recent work has demonstrated the profound influence of dissolved paramagnetic oxygen on NMR transverse relaxation measurements in both bulk water and confined pore systems. Systematic relaxometry experiments showed that increasing oxygen concentration sharply reduces T₂ relaxation times in water, with values dropping from several seconds in de‐aerated samples to mere milliseconds at high oxygen loadings. When applied to model sandstone cores, dissolved O₂ levels comparable to atmospheric conditions led to relaxation behaviour of bulk water that mimicked that of pore-confined fluids. These findings underscore the necessity of rigorous oxygen control for low‐field NMR characterisation of fluid distributions and pore structure, as geospatial variation in oxygen partial pressure alone can perturb relaxation times by up to 60 % in fluid phases and 36 % in pore spaces.

Nuclear Magnetic Resonance Applications in Porous Media Characterization publication trend

The graph below shows the total number of articles in nuclear magnetic resonance applications in porous media characterization across all publications each year (not limited to Nature Index journals).

Technical terms

Nuclear Magnetic Resonance (NMR): A technique that probes the magnetic properties of atomic nuclei to reveal structural and dynamic information about fluids and solids.

Transverse Relaxation Time (T₂): The characteristic time constant for decay of spin coherence due to interactions among magnetic moments and with pore surfaces.

Porosity: The fraction of a material’s volume that is occupied by voids or pores, indicating its capacity to store fluids.

Permeability: A measure of the ease with which a fluid can flow through interconnected pore networks.

Pore‐Size Distribution: The statistical distribution of pore diameters within a porous medium, key to understanding capillary and transport phenomena.

References

1. Effect of Fines Content on Pore Distribution of Sand/Clay Composite Soil. Sustainability (2023).
2. Low-field NMR investigations on dynamics of crude oil confined into nanoporous silica rods and white powder. Frontiers in Chemistry (2023).
3. A review on the applications of nuclear magnetic resonance (NMR) in the oil and gas industry: laboratory and field-scale measurements. Journal of Petroleum Exploration and Production Technology (2022).
4. Quantification of dissolved O2 in bulk aqueous solutions and porous media using NMR relaxometry. Scientific Reports (2021).