Slope of pseudo-steady state flow in pressure buildup test

Input(s)

Q: Flow Rate (STB/day)

B: Formation Volume Factor (bbl/STB)

$c_{t}$: Total Compressibility $(1 / \mathrm{psi})$

A: Drainage Area $\left(\mathrm{ft}^{2}\right)$

$\emptyset$: Porosity (fraction)

$\mathrm{h}$: Thickness (ft)

Output(s)

$m_{p s s}$: Slope $(\mathrm{psi} / \mathrm{h})$

Formula(s)

$$ m_{p s s}=\frac{0.23396 * Q * B}{c_{t} * A * h * \phi} $$

Reference(s)

Ahmed, T., McKinney, P.D. 2005. Advanced Reservoir Engineering, Gulf Publishing of Elsevier, Chapter: 1, Page: 33 .