Somerton method for formation permeability in coalbed methane reservoirs

Input(s)

$\mathrm{k}_{\mathrm{o}}$: Original Permeability at Zero Net Stress $(\mathrm{mD})$

$\Delta \sigma$: Net Stress (psi)

Output(s)

k: Permeability $(\mathrm{mD})$

Formula(s)

$$ \mathrm{k}=\mathrm{k}_{\mathrm{o}} *\left(\exp \left(\frac{(-0.003) * \Delta \sigma}{\mathrm{k}_{\mathrm{o}}^{0.1}}\right)+0.0002 *\left((\Delta \sigma)^{\frac{1}{3}}\right) *\left(\left(\mathrm{k}_{\mathrm{o}}\right)^{\frac{1}{3}}\right)\right) $$

Reference(s)

Ahmed, T., McKinney, P.D. 2005, Advanced Reservoir Engineering, Gulf Publishing of Elsevier, Chapter: 3, Page: 226 .