Relationship between SSP and Rw (NaCl predominant)
Input(s)
\(R_{(m f)_{e q}}\): Equivalent Resistivity of Mud Filtrate (ohm m)
\(\mathrm{K}\): Equilibrium Constant \((\mathrm{mV})\)
A: Proportionality Factor (dimensionless)
\(a_{w}\): Activity of \(\mathrm{NaCl}\) (dimensionless)
Output(s)
\(\left(R_{w}\right)_{e q}\): Equivalent Resistivity of Formation Water (ohm m)
SSP: Static Self Potential (V)
Formula(s)
\[
\begin{gathered}
\left(R_{w}\right)_{e q}=\left(\frac{A}{a_{w}}\right) \\
S S P=-K * \log \left(\left(\frac{R_{(m f)_{e q}}}{\left(R_{w}\right)_{e q}}\right)\right)
\end{gathered}
\]
Reference(s)
Bassiouni, Z., 1994, Theory, Measurement, and Interpretation of Well Logs. SPE Textbook Series Vol. 4. Chapter 6, Page: 133.