On the Validity of the “Thin” and “Thick” Double-Layer Assumptions When Calculating Streaming Currents in Porous Media
Figure 7
Critical capillary radius (determined from Figure 6) above which the thin double-layer approximation is valid (solid lines) and below which the thick double-layer assumption is valid (dashed lines), as a function of electrolyte concentration. Curves correspond to surface charge values of 1, 5, 10, 50, and 100 mC·m−2. Also shown are typical ranges of pore and pore-throat radii in sandstones and mudstones [7–10].
