Research Article

Frequency-Dependent Streaming Potential of Porous Media—Part 2: Experimental Measurement of Unconsolidated Materials

Table 1

Physical properties of the sample material.

PropertyUnitOttawa sandGlass beadsComment
0. 5 mm1 mm2 mm

Modal grain radius (laser diffraction), Using a Malvern Mastersizer 2000.
Modal grain radius (image analysis), Image analysis using Sigma Scan 4.
Modal grain radius (Hg injection), Calculated from pressure data using Mayer-Stowe theory.
D10 grain radius (sieving),
Effective pore radius, Using the method of Glover and Walker [12].
Effective pore throat radius, Using Glover and Déry [17], for random packing.
Modal pore throat radius (Hg injection), Using a Micromeritics AutoPore IV
Porosity (gravimetry)0.3140.3830.3800.382Please see text.
Porosity (helium expansion)0.3250.3910.3830.385Using a real gas expansion pycnometer.
Porosity (mercury injection)0.304Using a Micromeritics AutoPore IV.
Measured permeability, m2 The measured permeability at 5 Hz for the Ottawa sand and under steady-state conditions for the glass beads.
Predicted permeability using the RGPZ method, m2 Permeability predicted from electrical data and the grain diameter using the method of Glover et al. [26].
Electrical conductivity, S/m For a 0.001 mol/L NaCl at 25°C.
Electrical conductivity of the fluid, S/m Measured on the recycled fluid at the sample outlet after equilibration.
Formation factor, 4.6764.134.184.16Calculated from the conductivities of the saturated rock and the saturating fluid.
Connectedness, 0.2140.2420.2390.241Calculated from the formation factor [33, 34].
Cementation exponent, 1.3721.481.481.48Calculated from the formation factor.
Electrical tortuosity, 1.5191.5831.5891.588Calculated from the porosity and .
Theta factor, Θ3.7053.533.573.55From the method of [12].
Predicted transition frequency, Hz256.48213.3657.3212.61At 24°C using the method of [19].