Formation resistivity and porosity relations for carbonate rocks
Input(s)
a: Constant (Range of 2.2 to 2.5 ) (dimensionless)
\(\Phi\): Porosity (dimensionless)
Output(s)
\(F_{c}\): Formation Resistivity Factor for Chalky Rocks (dimensionless)
\(F_{c} O\): Formation Resistivity Factor for Compact Rocks (dimensionless)
\(F_{l}\): Formation Resistivity Factor for Low Porosity and non-fractured Carbonates, Shell Equation (dimensionless)
Formula(s)
\[
\begin{gathered}
F_{c}=\frac{1}{(\Phi)^{2}} \\
F_{c} O=\frac{1}{(\Phi)^{a}} \\
F_{l}=\frac{1}{(\Phi)^{1.87+\left(\frac{0.019}{\Phi}\right)}}
\end{gathered}
\]
Reference(s)
Bassiouni, Z., 1994, Theory, Measurement, and Interpretation of Well Logs. SPE Textbook Series Vol. 4. Chapter 1, Page: 10.