# Generalized relationship between formation resistivity factor and porosity (Chevron formula)

## Input(s)

\(\Phi\): Porosity (dimensionless)

## Output(s)

F: Formation Resistivity Factor (dimensionless)

## Formula(s)

\[
F=\frac{1.13}{(\Phi)^{1.73}}
\]

## Reference(s)

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