Formula 4.66
Principal stress due to petro-static pressure (hydraulic fracturing)
Input(s)
$\gamma$ : Average Specific Weight of Formation $\left(\mathrm{p} / \mathrm{cm}^{3}\right)$
$h$: Depth $(\mathrm{m})$
Output(s)
$\sigma_{z}$: Principal Stress in z-axis $\left(\mathrm{kp} / \mathrm{cm}^{2}\right)$
Formula(s)
$$ \sigma_{z}=\frac{\gamma \cdot h}{10} $$
Reference(s)
Saydam, T., (1967). Principles of Hydraulic Fracturing, ARI Publishing Co., Page: 5.