# Relationship between rock resistivity and water saturation

## Input(s)

F: Formation Resistivity Factor (dimensionless)

\(R_{w}\): Formation Water Resistivity (ohm m)

\(R_{t}\): Rock Resistivity (ohm m)

\(\mathrm{n}\): Saturation Exponent (dimensionless)

## Output(s)

\(S_{w}\): Water Saturation (fraction)

## Formula(s)

\[
S_{w}=\left(\frac{F * R_{w}}{R_{t}}\right)^{\frac{1}{n}}
\]

## Reference(s)

Bassiouni, Z., 1994, Theory, Measurement, and Interpretation of Well Logs. SPE Textbook Series Vol. 4. Chapter 1, Page: 11.