Cumulative effective compressibility - Fetkovich

Input(s)

$S_{w i}$: Initial Water Saturation (fraction)

$\bar{c}_{w}$: Cumulative Total Water Compressibility $(1 / \mathrm{psi})$

M: Dimensionless Volume Ratio (dimensionless)

$\bar{c}_{f}$: Total PV (Formation) Compressibility $\left(\mathrm{psi}^{-1}\right)$

Output(s)

$\bar{c}_{e}$: Effective Compressibility $(1 / \mathrm{psi})$

Formula(s)

$$ \bar{c}_{e}=\frac{S_{w i} * \bar{c}_{w}+M *\left(\bar{c}_{f}+\bar{c}_{w}\right)+\bar{c}_{f}}{1-S_{w i}} $$

Reference(s)

Ahmed, T., McKinney, P.D. 2005. Advanced Reservoir Engineering, Gulf Publishing of Elsevier, Chapter: 3, Page: 215,216 .