Gamma ray log shale index
Input(s)
\(G R_{c l}\): Log Response in Clean Beds (API)
\(G R_{s h}\): Log Response in Shale Beds (API)
GR: Log Response in Zone of Interest (API)
Output(s)
\(I_{G R}\): Gamma Ray Shale Index (fraction)
Formula(s)
\[
I_{G R}=\frac{G R-G R_{c l}}{G R_{s h}-G R_{c l}}
\]
Reference(s)
Core Laboratories. 2015. Formation Evaluation and Petrophysics, Page: 63.