# Formation resistivity and porosity relations from well log data based on Porter and Carothers data

## Input(s)

\(\Phi\): Porosity (dimensionless)

## Output(s)

\(F_{g}\): Formation Resistivity Factor for California Pliocene (dimensionless)

\(F_{c}\): Formation Resistivity Factor for U.S Gulf Coast Miocene (dimensionless)

## Formula(s)

\[
\begin{aligned}
& F_{g}=\frac{2.45}{(\Phi)^{1.08}} \\
& F_{c}=\frac{1.97}{(\Phi)^{1.29}}
\end{aligned}
\]

## Reference(s)

Bassiouni, Z., 1994, Theory, Measurement, and Interpretation of Well Logs. SPE Textbook Series Vol. 4. Chapter 1, Page: 9.