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.