Pore pressure of shale (Traugott)
Input(s)
z: Depth (ft)
\(S_{v}\): Sonic Velocity \((\mathrm{ft} / \mathrm{s})\)
\(R_{o}\): Resistivity of Shale (ohm \(\mathrm{ft}\) )
\(R_{n}\): Expected Resistivity (ohm ft)
\(\left(P_{p}\right)^{\text {hydro }}\): Hydrostatic Pore Pressure (psi)
Output(s)
\(P_{p s h}\): Pore Pressure of Shale (psi)
Formula(s)
\[
\mathrm{P}_{\mathrm{psh}}=\mathrm{z} *\left(\left(\frac{\mathrm{S}_{\mathrm{v}}}{\mathrm{z}}\right)-\left(\left(\frac{\mathrm{S}_{\mathrm{v}}}{\mathrm{z}}\right)-\left(\frac{\left(\mathrm{P}_{\mathrm{p}}\right)^{\text {hydro }}}{\mathrm{z}}\right)\right) *\left(\left(\frac{\mathrm{R}_{\mathrm{o}}}{\mathrm{R}_{\mathrm{n}}}\right)^{1.2}\right)\right)
\]
Reference(s)
Mark D. Zoback, Reservoir Geomechanics, Cambridge University Press, UK, Page: 47.