Formula 11.72

Stress intensity at tip of mode I fracture

Input(s)

$\mathrm{P}_{\mathrm{f}}$: Fracture Pressure $(\mathrm{psi})$

$\mathrm{S}_{\mathrm{c}}$: Minimum Principle Stress $(\mathrm{psi})$

L: Length of Fracture (ft)

Output(s)

K: Stress Intensity (psi ft)

Formula(s)

$$ \mathrm{K}=\left(\mathrm{P}_{\mathrm{f}}-\mathrm{S}_{\mathrm{c}}\right) * \pi *\left(\mathrm{~L}^{0.5}\right) $$

Reference(s)

Mark D. Zoback, Reservoir Geomechanics, Cambridge University Press, UK, Page: 122.