Parameter

Equation

Reference

Shale Volume (Vsh)

Using Gamma Ray Log

$I_{GR}=\frac{G{R}_{\log }-G{R}_{\min }}{G{R}_{\max }-G{R}_{\min }}$

$V_{sh}=0.083\left(2^{3.7\ast I_{GR}}-1\right)$

Bassiouni, 1994

Shale Volume (Vsh)

Using Resistivity Log

$Z=\frac{R_{clay}}{R_t}\times \frac{\left(R_{clean}-R_t\right)}{\left(R_{clean}-R_{clay}\right)}$

For R_t greater than 2*R_clay then

$V_{shRes}=0.5\times {\left(2\times Z\right)}^{0.67\times \left(z+1\right)}$

Otherwise,

$V_{shRes}=Z$

Schlumberger, 2007

Density Porosity ( ${\varphi }_{Dcorr}$ )

${\varphi }_{Dcorr}=\left(\frac{{\rho }_{ma}-{\rho }_b}{{\rho }_{ma}-{\rho }_f}\right)-Vsh\left(\frac{{\rho }_{ma}-{\rho }_{sh}}{{\rho }_{ma}-{\rho }_f}\right)$

Dresser, 1975

Neutron Porosity ( ${\varphi }_{Ncorr}$ )

${\varphi }_{Ncorr}={\varphi }_{\text{N}}-\left[\left(\frac{{\varphi }_{\text{Nsh}}}{0.45}\right)\times 0.30\times V_{sh}\right]$

Dresser, 1975

Average Porosity ( ${\varphi }_{N-D}$ )

${\varphi }_{N-D}=\sqrt{\frac{{\varphi }_{{}_{Ncorr}}^2+{\varphi }_{Dcorr}^2}{2.0}}$

Salley, 1998;

Asqith & Krygowski, 2004

Water Saturation (Sw)

(Poupon-Leveaux)

$\frac{1}{\sqrt{R_t}}=\left(\sqrt{\frac{{\varphi }^m}{a\times R_w}}+\frac{V_{sh}{}^{\left(1-\frac{V_{sh}}{2}\right)}}{\sqrt{R_{sh}}}\right)\times S_{{}_w}^{{}^{\frac{n}{2}}}$

Schlumberger, 2007

Hydrocarbon Saturation (S_h)

$S_h=1-S_W$

Bassiouni, 1994

Residual Hydrocarbon Saturation (S_hr)

$S_{xo}=\sqrt{\frac{F\ast R_{mf}}{R_{XO}}}$

$S_{hr}=1-S_{xo}$

Bassiouni, 1994

Permeability (k)

Timur Model

$K=8581\ast \frac{{\varphi }^{4.4}}{Swir{r}^2}$

Brock, 1986

Permeability (k)

Schlumberger Model

$K=10000\ast \frac{{\varphi }^{4.5}}{Swir{r}^2}$

Brock, 1986

Flow Capacity (Fm)

$F_m=\frac{{\displaystyle {\sum }_{i=1}^m{k}_i{h}_i}}{{\displaystyle {\sum }_{i=1}^n{k}_i{h}_i}};m=1,\dots ,n$

Gunter, et al., 1997

Storage Capacity (Фm)

${\Phi }_m=\frac{{\displaystyle {\sum }_{i=1}^m{\Phi }_i{h}_i}}{{\displaystyle {\sum }_{i=1}^n{\Phi }_i{h}_i}};m=1,\dots ,n$

Gunter, et al., 1997