Porous Media

Small-scale instrumentation for nuclear magnetic resonance of porous media

The investigation of fluids confined to porous media is the oldest topic of investigation with small-scale nuclear magnetic resonance (NMR) instruments, as such instruments are mobile and can be moved to the site of the object, such as the borehole of an oil well. While the analysis was originally restricted by the inferior homogeneity of …

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Molecular exchange ofn-hexane in zeolite sieves studied by diffusion–diffusion and T1-diffusion nuclear magnetic resonance exchange spectroscopy

Molecular exchange properties and diffusion of n-hexane embedded in a bimodal pore structure with characteristic length scales in the order of nano and micrometres, respectively, formed by packing of zeolite particles, are studied. Two-dimensional (2D) nuclear magnetic resonance (NMR) diffusion correlation experiments together with relaxation–diffusion correlation experiments are performed at low magnetic field using a single-sided …

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Permeability Prediction for Low Porosity Rocks by Mobile NMR

Estimating permeability from NMR well logs or mobile NMR core scanner data is an attractive method as the measurements can be performed directly in the formation or on fresh cores right after drilling. Furthermore, the method is fast and non-destructive. Compared to T1 relaxation times, commonly measured T2 distributions are influenced by external and internal magnetic field gradients. We …

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Quantitative NMR monitoring of liquid ingress into repellent heterogeneous layered fabrics

Fabrics which are water repellent and repellent to other liquids are often constructed using multiple layers of material. Such a construction is preferable to a single layer of a liquid-repellent textile because, under the action of an applied pressure, ingress of a liquid through the first layer can be halted by the second or subsequent …

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Magnetic Resonance in Porous Media: Recent Progress

Recent years have seen significant progress in the NMR study of porous media from natural and industrial sources and of cultural significance such as paintings. This paper provides a brief outline of the recent technical development of NMR in this area. These advances are relevant for broad NMR applications in material characterization. Song, Yi-Qiao, et al. “Magnetic Resonance in Porous Media: Recent Progress.” The …

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Application of a Portable Nuclear Magnetic Resonance Surface Probe to Porous Media

A portable nuclear magnetic resonance (NMR) surface probe was used to determine the time-dependent self-diffusion coefficient D(t) of water molecules in two fluid-filled porous media. The measuring equipment and the inhomogeneous magnetic fields in the sensitive volume of the probe are described. It is discussed how to evaluate D(t) using a surface probe from the primary and stimulated echoes generated in three-pulse experiments. Furthermore, …

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Water Absorption Kinetics in Different Wettability Conditions Studied at Pore and Sample Scales in Porous Media by NMR with Portable Single-Sided and Laboratory Imaging Devices

NMR relaxation time distributions of water 1H obtained by a portable single-sided surface device have been compared with MRI internal images obtained with a laboratory imaging apparatus on the same biocalcarenite (Lecce Stone) samples during capillary water uptake. The aim of this work was to check the ability of NMR methods to quantitatively follow the absorption phenomenon under different wettability conditions of the …

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Porosity and Permeability from Mobile NMR Core-Scanning

Two types of mobile Nuclear Magnetic Resonance (NMR) core-scanners were used to measure porosity and estimate the pore-size distribution of water-saturated drill cores. Both devices are experimental prototypes and differ in their magnetic field strength and homogeneity. Whereas the magnetic field of the unilateral NMR-MOUSE® is applied to the sample from one side and is …

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Mobile NMR Device for Measurements of Porosity and Pore Size Distributions of Drilled Core Samples

A new mobile NMR scanner has been designed with a Halbach magnet for measurements of porosity and pore‐size distributions of water‐saturated cylindrical geological cores with diameters up to 60 mm. It is light (∼8 kg) and has a sufficiently homogeneous magnetic field in a large and accessible cylindrical volume. Practical aspects of the sensor construction …

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