Frame bulk and shear moduli of air and water saturated glass beads

1999 ◽  
Vol 106 (4) ◽  
pp. 2131-2132
Author(s):  
Masao Kimura
Keyword(s):  
Glass Beads ◽  
Shear Moduli ◽  
Water Saturated

Dynamic acoustoelastic testing of weakly pre-loaded unconsolidated water-saturated glass beads

2010 ◽  
Vol 128 (6) ◽  
pp. 3344-3354 ◽  
Author(s):  
Guillaume Renaud ◽  
Samuel Callé ◽  
Marielle Defontaine
Keyword(s):  
Glass Beads ◽  
Water Saturated

Changes in dynamic shear moduli of carbonate rocks with fluid substitution

Geophysics ◽  
2009 ◽  
Vol 74 (3) ◽  
pp. E135-E147 ◽  
Author(s):  
Gregor T. Baechle ◽  
Gregor P. Eberli ◽  
Ralf J. Weger ◽  
Jose Luis Massaferro
Keyword(s):  
Shear Modulus ◽  
Shear Wave ◽  
Wave Velocity ◽  
Shear Wave Velocity ◽  
Water Saturation ◽  
Acoustic Properties ◽  
P Wave ◽  
Shear Moduli ◽  
Water Saturated ◽  
Fluid Interaction

To assess saturation effects on acoustic properties in carbonates, we measure ultrasonic velocity on 38 limestone samples whose porosity ranges from 5% to 30% under dry and water-saturated conditions. Complete saturation of the pore space with water causes an increase and decrease in compressional- and shear-wave velocity as well as significant changes in the shear moduli. Compressional velocities of most water-saturated samples are up to [Formula: see text] higher than the velocities of the dry samples. Some show no change, and a few even show a decrease in velocity. Shear-wave velocity [Formula: see text] generally decreases, but nine samples show an increase of up to [Formula: see text]. Water saturation decreases the shear modulus by up to [Formula: see text] in some samples and increases it by up to [Formula: see text] in others. The average increase in the shear modulus with water saturation is [Formula: see text]; the average decrease is [Formula: see text]. The [Formula: see text] ratio shows an overall increase with water saturation. In particular, rocks displaying shear weakening have distinctly higher [Formula: see text] ratios. Grainstone samples with high amounts of microporosity and interparticle macro-pores preferentially show shear weakening, whereas recrystallized limestones are prone to increase shear strengths with water saturation. The observed shear weakening indicates that a rock-fluid interaction occurs with water saturation, which violates one of the assumptions in Gassmann’s theory. We find a positive correlation between changes in shear modulus and the inability of Gassmann’s theory to predict velocities of water-saturated samples at high frequencies. Velocities of water-saturated samples predicted by Gassmann’s equation often exceed measured values by as much as [Formula: see text] for samples exhibiting shear weakening. In samples showing shear strengthening, Gassmann-predicted velocity values are as much as [Formula: see text] lower than measured values. In 66% of samples, Gassmann-predicted velocities show a misfit to measured water-saturated P-wave velocities. This discrepancy between measured and Gassmann-predicted velocity is not caused solely by velocity dispersion but also by rock-fluid interaction related to the pore structure of carbonates. Thus, a pore analysis should be conducted to assess shear-moduli changes and the resultant uncertainty for amplitude variation with offset analyses and velocity prediction using Gassmann’s theory.

Complex conductivity of water-saturated packs of glass beads

2008 ◽  
Vol 321 (1) ◽  
pp. 103-117 ◽  
Author(s):  
P. Leroy ◽  
A. Revil ◽  
A. Kemna ◽  
P. Cosenza ◽  
A. Ghorbani
Keyword(s):  
Glass Beads ◽  
Complex Conductivity ◽  
Water Saturated

scholarly journals Experiments on Thermal Convection in Snow

1985 ◽  
Vol 6 ◽  
pp. 43-47 ◽  
Author(s):  
D. Powers ◽  
S.C. Colbeck ◽  
K. O'Neill
Keyword(s):  
Heat Transfer ◽  
Thermal Convection ◽  
Glass Beads ◽  
Experimental Results ◽  
Onset Of Convection ◽  
Snow Metamorphism ◽  
Water Saturated

Thermal convection is observed in snow and in a compact of water-saturated glass beads. While uncertainty in the permeability of the snow limits our ability to compare the observed and calculated onset of convection, agreement between the observed and calculated effects of convection on heat transfer in snow is good. Experimental results with glass beads agree with both the calculated onset of and heat transfer by convection. Attempts are made to assess the effects of convection on snow metamorphism. While much is still uncertain about the significance of thermal convection in snow, it is clear that the phenomenon does occur.

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