TY - JOUR
T1 - A laboratory study of the effect of clay, silt, and sand content on low-field nuclear magnetic resonance relaxation time distributions
AU - Peng, Yonghui
AU - Keating, Kristina
N1 - Publisher Copyright:
© 2021 Society of Exploration Geophysicists.
PY - 2021/6/17
Y1 - 2021/6/17
N2 - We have developed a laboratory nuclear magnetic resonance (NMR) study to investigate the effect of clay, silt, and sand content on the NMR relaxation time distribution. Transverse NMR relaxation times (T2) are determined for water-saturated unconsolidated sediment mixtures of 1%-60% kaolinite clay, 5%-85% silt-size glass beads, and 8%-94% quartz sand by mass. Nearly all of the mixtures are characterized by a unimodal T2 distribution. When clay is present in quantities greater than 10%, the clay content dominates the response. For these samples, the mean-log relaxation times (T2ML) range from 0.03 to 0.06 s, regardless of silt or sand content. For mixtures with <10% clay, T2ML decreases with increasing clay content. When the clay content is kept the same, T2ML decreases with increasing silt content and increases with the increasing sand content. The strong effect of the clay content on the NMR response is due to the high specific surface area of the clay and the distribution of clay throughout the samples. These results will help improve the interpretation of NMR field data in soils and unconsolidated sediments.
AB - We have developed a laboratory nuclear magnetic resonance (NMR) study to investigate the effect of clay, silt, and sand content on the NMR relaxation time distribution. Transverse NMR relaxation times (T2) are determined for water-saturated unconsolidated sediment mixtures of 1%-60% kaolinite clay, 5%-85% silt-size glass beads, and 8%-94% quartz sand by mass. Nearly all of the mixtures are characterized by a unimodal T2 distribution. When clay is present in quantities greater than 10%, the clay content dominates the response. For these samples, the mean-log relaxation times (T2ML) range from 0.03 to 0.06 s, regardless of silt or sand content. For mixtures with <10% clay, T2ML decreases with increasing clay content. When the clay content is kept the same, T2ML decreases with increasing silt content and increases with the increasing sand content. The strong effect of the clay content on the NMR response is due to the high specific surface area of the clay and the distribution of clay throughout the samples. These results will help improve the interpretation of NMR field data in soils and unconsolidated sediments.
KW - laboratory experiments
KW - nuclear magnetic resonance
KW - transverse relaxation
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U2 - 10.1190/geo2020-0621.1
DO - 10.1190/geo2020-0621.1
M3 - Article
AN - SCOPUS:85118308116
SN - 0016-8033
VL - 86
SP - WB1-WB8
JO - GEOPHYSICS
JF - GEOPHYSICS
IS - 5
ER -