DR RELAXO
FFC-NMR consultancy service
Rocks and Clays
Rocks and clays were the first successes for the 3-Tau Model.
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Below are the two examples of NMRD profiles fit using the 3TM software. One, a synthetic clay from Zavada and co-workers [J. Chem. Phys. 110, 6977 (1999)] is free from paramagnetic ions, whereas the oil-bearing shale contains two fluid types and manganese ions.
Please contact DR Relaxo if you would like information and/or support on FFC NMR applied to rocks and clays.
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Saponite clay
Saponite clay is an artificial clay clear of paramagnetic ion impurities.
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The dotted line is the relaxation rate contribution due to bulk water.
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The dashed line is the relaxation rate contribution due to surface water.
Notice that the surface water contribution overwhelmingly dominates except in the fixed field NMR frequency range greater than1 MHz
Oil-bearing shale (HH model)
The rock contained manganese impurities leading to two relaxation rate contributions:
1) the dotted line is due to interactions between Mn(II) and bulk water, and
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2) the dashed line is due to interactions between Mn(II) and bulk water.
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This was a bespoke application of the 3TM model in which the optimum fit (solid line) was achieved assuming that the rock surfaces were only 20% covered by a single layer of oil.