Dimensionless pressure (linear flow/constant rate production/general case)

Input(s)

$p_{i}$: Initial Reservoir Pressure $(\mathrm{psi})$

B: Volume Factor $(\mathrm{RB} / \mathrm{STB})$

$\mu$: Oil Viscosity $(\mathrm{cP})$

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

A: Cross Section Area (ft)

q: Flow Rate (STB/day)

p: Pressure $(\mathrm{psi})$

Output(s)

$p_{D}$: Dimensionless Pressure (dimensionless)

Formula(s)

$$ p_{D}=\frac{k * A^{0.5}}{141.2 * q * B * \mu} *\left(p_{i}-p\right) $$

Reference(s)

Lee, J., Rollins, J. B., \& Spivey, J. P. (2003). Pressure Transient Testing (Vol. 9). Richardson, Texas: Society of Petroleum Engineers, Page: 9.