Resistivity of a water-saturated shaly sand (Vsh models)
Input(s)
\(R_{w}\): Formation Water Resistivity (ohm m)
\(V_{s h}\): Bulk Volume Fraction of Shale (fraction)
\(R_{s h}\): Shale Resistivity (ohm m)
F: Formation Resistivity Factor (dimensionless)
Output(s)
\(\alpha\): Clay Distribution Factor (dimensionless)
\(\beta\): Clay Distribution Factor (dimensionless)
\(\frac{1}{R_{o}}\): Formation Hydrocarbon Resistivity (per(ohm m))
Formula(s)
\[
\begin{gathered}
\alpha=\left(\frac{V_{s h}}{R_{s h}}\right) \\
\beta=\frac{1}{F} \\
\frac{1}{R_{o}}=(\alpha)+\left(\frac{\beta}{R_{w}}\right)
\end{gathered}
\]
Reference(s)
Bassiouni, Z., 1994, Theory, Measurement, and Interpretation of Well Logs. SPE Textbook Series Vol. 4. Chapter 1, Page: 16.