Formation factor - Archie's equation

Input(s)

a: Tortuosity Factor (dimensionless)

$\Phi$: Porosity (fraction)

m: Cementation Factor (dimensionless)

Output(s)

$F$: Formation Factor (dimensionless)

Formula(s)

$$ F=\frac{a}{\Phi^{m}} $$

Notes: $a$ and $m$ are measured from log-log plot of $F$ vs Porosity.

Reference(s)

Core Laboratories. 2005. Formation Evaluation and Petrophysics, Page: 38.