Fraction of total porosity occupied by clays

Input(s)

$\Phi_{S}$: Sonic Log Porosity (fraction)

$\Phi_{D}$: Density Log Porosity (fraction)

Output(s)

q: Fraction of the Total Porosity Occupied by Clays (fraction)

Formula(s)

$$ q=\frac{\left(\Phi_{S}\right)-\left(\Phi_{D}\right)}{\Phi_{S}} $$

Reference(s)

Core Laboratories. 2005: Formation Evaluation and Petrophysics, Page: 98.