Formula 3.31
Dimensionless time (linear flow/constant rate production/general case)
Input(s)
$\mathrm{t}$: Production Time $(\mathrm{h})$
k: Permeability $(\mathrm{mD})$
$\emptyset$: Porosity (fraction)
$c_{t}$: Total Compressibility $(1 / \mathrm{psi})$
$\mu$: Oil Viscosity $(\mathrm{cP})$
A: Cross Sectional Area (ft)
Output(s)
$t_{A D}$: Dimensionless Time (dimensionless)
Formula(s)
$$ t_{A D}=\frac{0.0002637 * k * t}{\phi * \mu * c_{t} * A} $$
Reference(s)
Lee, J., Rollins, J. B., \& Spivey, J. P. (2003). Pressure Transient Testing (Vol. 9). Richardson, Texas: Society of Petroleum Engineers, Page: 9.