Axial stress around vertical wellbore

Input(s)

R: Radius of Wellbore (ft)

$\mathrm{r}$: Position in Respect to Centre of Wellbore (ft)

$\Theta$: Azimuth of $\mathrm{S}_{\mathrm{hmax}}(\mathrm{rad})$

$\mathrm{S}_{\mathrm{hmax}}$: Maximum Horizontal Stress (psi)

$\mathrm{S}_{\mathrm{hmin}}$: Minimum Horizontal Stress (psi)

Output(s)

$\tau$: Twisting Stress (psi)

Formula(s)

Reference(s)

Mark D. Zoback, Reservoir Geomechanics, Cambridge University Press, UK, Page: 170.