scholarly journals In situ effective diffusion coefficient profiles in live biofilms using pulsed-field gradient nuclear magnetic resonance

2010 ◽  
Vol 106 (6) ◽  
pp. 928-937 ◽  
Author(s):  
Ryan S. Renslow ◽  
Paul D. Majors ◽  
Jeffrey S. McLean ◽  
Jim K. Fredrickson ◽  
Bulbul Ahmed ◽  
...  
Keyword(s):  
Nuclear Magnetic Resonance ◽  
Diffusion Coefficient ◽  
Magnetic Resonance ◽  
Field Gradient ◽  
Effective Diffusion Coefficient ◽  
Effective Diffusion ◽  
Pulsed Field ◽  
Nuclear Magnetic

New Technique for Evaluating Fracture Geometry and Preferential Orientation Using Pulsed Field Gradient Nuclear Magnetic Resonance

SPE Journal ◽  
2021 ◽  
pp. 1-14
Author(s):  
Mahmoud Elsayed ◽  
Ammar El-Husseiny ◽  
Hyung Kwak ◽  
Syed Rizwanullah Hussaini ◽  
Mohamed Mahmoud
Keyword(s):  
Nuclear Magnetic Resonance ◽  
Diffusion Coefficient ◽  
Fluid Flow ◽  
Magnetic Resonance ◽  
Field Gradient ◽  
Preferential Orientation ◽  
Pore Geometry ◽  
Pulsed Field ◽  
Pfg Nmr

Summary In-situ evaluation of fracture tortuosity (i.e., pore geometry complexity and roughness) and preferential orientation is crucial for fluid flow simulation and production forecast in subsurface water and hydrocarbon reservoirs. This is particularly significant for naturally fractured reservoirs or postacid fracturing because of the strong permeability anisotropy. However, such downhole in-situ characterization remains a challenge. This study presents a new method for evaluating fracture tortuosity and preferential orientation based on the pulsed field gradient (PFG) nuclear magnetic resonance (NMR) technique. Such an approach provides diffusion tortuosity, τd, defined as the ratio of bulk fluid diffusion coefficient to the restricted diffusion coefficient in the porous media. In the PFG NMR technique, the magnetic field gradient can be applied in different directions, and therefore anisotropy in diffusion coefficient and τd can be evaluated. Three 3D printed samples, characterized by well controlled variable fracture tortuosity, one fractured sandstone, and three acidized carbonate samples with wormhole were used in this study. PFG NMR measurements were performed using both 2- and 12-MHz NMR instruments to obtain τd in the three different principal directions. The results obtained from the NMR measurements were compared with fracture tortuosity and preferential orientation determined from the microcomputed tomography (micro-CT) images of the samples. The results showed that τd increases as the fracture tortuosity and pore geometry complexity increases, showing good agreement with the image-based geometric tortuosity values. Moreover, the lowest τd values were found to coincide with the preferential direction of fracture surfaces and wormhole body for a given sample, whereas the maximum τd values correspond to the nonconnected pathway directions. These results suggest that the implantation of directional restricted diffusion measurements on the NMR well logging tools would offer a possibility of probing tortuosity and determining preferential fluid flow direction via direct downhole measurements.

High-temperature pulsed field gradient nuclear magnetic resonance self-diffusion measurements of n-alkanes in MFl-type zeolites

1992 ◽  
Vol 88 (23) ◽  
pp. 3505-3509 ◽  
Author(s):  
Wilfried Heink ◽  
Jörg Kärger ◽  
Harry Pfeifer ◽  
Klaas P. Datema ◽  
Andreas K. Nowak
Keyword(s):  
Nuclear Magnetic Resonance ◽  
High Temperature ◽  
Magnetic Resonance ◽  
Field Gradient ◽  
Pulsed Field ◽  
Self Diffusion ◽  
Nuclear Magnetic

Probe Molecules for Pulsed‐Field‐Gradient Diffusion Nuclear Magnetic Resonance Experiments on Micelles

2019 ◽  
Vol 23 (2) ◽  
pp. 319-325
Author(s):  
Mark D. Lingwood ◽  
Benjamin J. Schepergerdes ◽  
Deja‐Monae T. Hermosillo ◽  
Jalissa N. Delgado ◽  
Kaya P. Sanders
Keyword(s):  
Nuclear Magnetic Resonance ◽  
Magnetic Resonance ◽  
Field Gradient ◽  
Probe Molecules ◽  
Pulsed Field ◽  
Gradient Diffusion ◽  
Nuclear Magnetic

scholarly journals Diffusion Coefficients of Carbon Dioxide in Brines Measured Using 13C Pulsed-Field Gradient Nuclear Magnetic Resonance

2014 ◽  
Vol 60 (1) ◽  
pp. 181-184 ◽  
Author(s):  
Shane P. Cadogan ◽  
Jason P. Hallett ◽  
Geoffrey C. Maitland ◽  
J. P. Martin Trusler
Keyword(s):  
Carbon Dioxide ◽  
Nuclear Magnetic Resonance ◽  
Magnetic Resonance ◽  
Field Gradient ◽  
Diffusion Coefficients ◽  
Pulsed Field ◽  
Nuclear Magnetic

Diffusion of a Mixture of Methane and Xenon in Silicalite:  A Molecular Dynamics Study and Pulsed Field Gradient Nuclear Magnetic Resonance Experiments

1998 ◽  
Vol 102 (33) ◽  
pp. 6375-6381 ◽  
Author(s):  
Steffen Jost ◽  
Nils-Karsten Bär ◽  
Siegfried Fritzsche ◽  
Reinhold Haberlandt ◽  
Jörg Kärger
Keyword(s):  
Molecular Dynamics ◽  
Nuclear Magnetic Resonance ◽  
Magnetic Resonance ◽  
Field Gradient ◽  
Pulsed Field ◽  
Nuclear Magnetic
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