Nuclear magnetic resonance relaxivity and surface‐to‐volume ratio in porous media with a wide distribution of pore sizes

1996 ◽  
Vol 79 (7) ◽  
pp. 3656-3664 ◽  
Author(s):  
G. C. Borgia ◽  
R. J. S. Brown ◽  
P. Fantazzini
Keyword(s):  
Nuclear Magnetic Resonance ◽  
Porous Media ◽  
Magnetic Resonance ◽  
Volume Ratio ◽  
Wide Distribution ◽  
Pore Sizes ◽  
Nuclear Magnetic

Application of Low-Field Nuclear Magnetic Resonance (LFNMR) in Characterizing the Dissociation of Gas Hydrate in a Porous Media

2021 ◽  
Vol 35 (3) ◽  
pp. 2174-2182
Author(s):  
Yongchao Zhang ◽  
Lele Liu ◽  
Daigang Wang ◽  
Pengfei Chen ◽  
Zhun Zhang ◽  
...  
Keyword(s):  
Nuclear Magnetic Resonance ◽  
Porous Media ◽  
Magnetic Resonance ◽  
Gas Hydrate ◽  
Low Field ◽  
Nuclear Magnetic

Internal surfaces of porous media studied by nuclear magnetic resonance cryoporometry

1998 ◽  
Vol 108 (19) ◽  
pp. 8195-8198 ◽  
Author(s):  
S. G. Allen ◽  
P. C. L. Stephenson ◽  
J. H. Strange
Keyword(s):  
Nuclear Magnetic Resonance ◽  
Porous Media ◽  
Magnetic Resonance ◽  
Internal Surfaces ◽  
Nuclear Magnetic

Nuclear magnetic resonance microscopy of single neurons under hypotonic perturbation

1996 ◽  
Vol 271 (6) ◽  
pp. C1895-C1900 ◽  
Author(s):  
E. W. Hsu ◽  
N. R. Aiken ◽  
S. J. Blackband
Keyword(s):  
Nuclear Magnetic Resonance ◽  
Magnetic Resonance ◽  
Single Cells ◽  
Extracellular Volume ◽  
Relaxation Times ◽  
Volume Ratio ◽  
Cell Swelling ◽  
Single Neurons ◽  
Apparent Diffusion Coefficients ◽  
Nuclear Magnetic

Nuclear magnetic resonance (NMR) characteristics of water in perfused single neurons undergoing a 20% hypotonic perturbation were examined quantitatively using NMR microscopy. The transverse relaxation times (T2) in the cytoplasm and nucleus increased by 24.0 +/- 8.5% (average +/- SE, n = 8) and 29.7 +/- 5.3% (n = 6), respectively, whereas the apparent diffusion coefficients (ADC) showed no significant change. These findings are consistent with the behaviors of a perfect osmometer and with accepted molecular relaxation and diffusion models and have significant impacts on current views of properties of cellular water. Furthermore, the results suggest that the increase of tissue intracellular-to-extracellular volume ratio during cell swelling is the predominant mechanism underlying the ADC reduction in acute brain ischemia. These data are the first direct quantitative measurements of the NMR characteristics of water in the cytoplasm and nucleus of single cells undergoing physiological perturbations and may lead to an improved diagnostic capability for NMR imaging in a variety of disease states.

Pore-Size Distributions for Organic-Shale-Reservoir Rocks From Nuclear-Magnetic-Resonance Spectra Combined With Adsorption Measurements

SPE Journal ◽  
2015 ◽  
Vol 20 (04) ◽  
pp. 824-830 ◽  
Author(s):  
Richard F. Sigal
Keyword(s):  
Nuclear Magnetic Resonance ◽  
Magnetic Resonance ◽  
Pore Size ◽  
Surface Relaxation ◽  
Size Distributions ◽  
Pore Sizes ◽  
Pore Size Distributions ◽  
Shale Reservoirs ◽  
Organic Shale ◽  
Nuclear Magnetic

Summary The behavior of fluids in nanometer-scale pores can have a strong functional dependence on the pore size. In mature organic-shale reservoirs, the nuclear-magnetic-resonance (NMR) signal from methane decays by surface relaxation. The methane NMR spectrum provides an uncalibrated pore-size distribution for the pores that store methane. The distribution can be calibrated by calculating a pore-wall-surface area from a methane-Langmuir-adsorption isotherm. When this method was applied to samples from a reservoir in the dry-gas window, the pores containing methane had pore sizes that ranged from 1 to approximately 100 nm. Approximately 20–40% of the pore volume was in pores smaller than 10 nm, where deviation from bulk-fluid behavior can be significant. The samples came from two wells. The surface relaxivity for the sample from Well 2 was somewhat different from the relaxivity for the two samples from Well 1. Samples that adsorbed more methane had smaller pore sizes. This methodology to obtain pore-size distributions should be extendable to more-general organic-shale reservoirs.

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