Formation resistivity  $//<![CDATA[ \begin{array}{l}R_t\end{array} //]]>$ is defined by mineralization of the rock matrix and saturating fluids.

The simplest and most practical models are based on:

• formation porosity  $//<![CDATA[ \begin{array}{l}\phi_e\end{array} //]]>$
  
  
• water-saturated shaliness  $//<![CDATA[ \begin{array}{l}V_{sh}\end{array} //]]>$
  
  
• water saturation volumetric share  $//<![CDATA[ \begin{array}{l}s_w\end{array} //]]>$

See Also

Petroleum Industry / Upstream / Subsurface E&P Disciplines / Petrophysics

Well & Reservoir Surveillance / Well logging / Reservoir Data Logs (RDL) / Saturation from Resistivity