Frequency domain surface nuclear magnetic resonance forward modeling on an adaptive octree mesh

2010 ◽  
Author(s):  
Trevor Irons ◽  
Yaoguo Li ◽  
Jason R. McKenna
Keyword(s):  
Nuclear Magnetic Resonance ◽  
Magnetic Resonance ◽  
Frequency Domain ◽  
Forward Modeling ◽  
Octree Mesh ◽  
Adaptive Octree Mesh ◽  
Nuclear Magnetic

New approaches of 3D nuclear magnetic resonance inversion for improving fluid typing

2016 ◽  
Vol 4 (2) ◽  
pp. SF67-SF79 ◽  
Author(s):  
Songhua Chen ◽  
Wei Shao ◽  
Ron Balliet
Keyword(s):  
Nuclear Magnetic Resonance ◽  
Magnetic Resonance ◽  
Forward Modeling ◽  
Inversion Method ◽  
Improved Method ◽  
3D Inversion ◽  
Nmr Logging ◽  
New Approaches ◽  
2D And 3D ◽  
Nuclear Magnetic

We have developed two new approaches for improving the efficiency and robostness of 2D and 3D inversion processing and interpretation from nuclear magnetic resonance (NMR) logging data. The first improved method consists of a dual-step inversion method to obtain [Formula: see text] and [Formula: see text] maps independently, rather than deriving one from the other. The second approach is an inversion-forward modeling-inversion technique for obtaining [Formula: see text] and [Formula: see text] maps using the same acquired data used for deriving [Formula: see text] and [Formula: see text] maps. Simulation results were evaluated to determine the improvement of the fluid typing interpretation and the robustness of the processing methods. Three actual wells of NMR logging data processing examples were also included to illustrate the utility of these methods for improving fluid typing involving various different combinations of reservoir fluids and mud filtrates.

An emerging technology: Nuclear magnetic resonance microscopy

1988 ◽  
Vol 46 ◽  
pp. 1000-1001
Author(s):  
M.J. Hennessy ◽  
E. Kwok
Keyword(s):  
Nuclear Magnetic Resonance ◽  
Magnetic Resonance ◽  
Relaxation Times ◽  
Basic Research ◽  
Local Environment ◽  
Magnetic Resonance Images ◽  
Nmr Microscopy ◽  
Mri Scans ◽  
Temperature Relaxation ◽  
Nuclear Magnetic

Much progress in nuclear magnetic resonance microscope has been made in the last few years as a result of improved instrumentation and techniques being made available through basic research in magnetic resonance imaging (MRI) technologies for medicine. Nuclear magnetic resonance (NMR) was first observed in the hydrogen nucleus in water by Bloch, Purcell and Pound over 40 years ago. Today, in medicine, virtually all commercial MRI scans are made of water bound in tissue. This is also true for NMR microscopy, which has focussed mainly on biological applications. The reason water is the favored molecule for NMR is because water is,the most abundant molecule in biology. It is also the most NMR sensitive having the largest nuclear magnetic moment and having reasonable room temperature relaxation times (from 10 ms to 3 sec). The contrast seen in magnetic resonance images is due mostly to distribution of water relaxation times in sample which are extremely sensitive to the local environment.

Nuclear magnetic resonance microscopy

1989 ◽  
Vol 47 ◽  
pp. 828-829
Author(s):  
Paul C. Lauterbur
Keyword(s):  
Magnetic Field ◽  
Nuclear Magnetic Resonance ◽  
Magnetic Resonance ◽  
Magnetic Fields ◽  
Signal To Noise ◽  
Field Gradients ◽  
Useful Signal ◽  
Magnetic Field Gradients ◽  
Observation Times ◽  
Nuclear Magnetic

Nuclear magnetic resonance imaging can reach microscopic resolution, as was noted many years ago, but the first serious attempt to explore the limits of the possibilities was made by Hedges. Resolution is ultimately limited under most circumstances by the signal-to-noise ratio, which is greater for small radio receiver coils, high magnetic fields and long observation times. The strongest signals in biological applications are obtained from water protons; for the usual magnetic fields used in NMR experiments (2-14 tesla), receiver coils of one to several millimeters in diameter, and observation times of a number of minutes, the volume resolution will be limited to a few hundred or thousand cubic micrometers. The proportions of voxels may be freely chosen within wide limits by varying the details of the imaging procedure. For isotropic resolution, therefore, objects of the order of (10μm) may be distinguished.Because the spatial coordinates are encoded by magnetic field gradients, the NMR resonance frequency differences, which determine the potential spatial resolution, may be made very large. As noted above, however, the corresponding volumes may become too small to give useful signal-to-noise ratios. In the presence of magnetic field gradients there will also be a loss of signal strength and resolution because molecular diffusion causes the coherence of the NMR signal to decay more rapidly than it otherwise would. This phenomenon is especially important in microscopic imaging.

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