Dimensionless time (radial flow/constant rate production)

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 $(\mathrm{cP})$

$r_{w}$: Wellbore Radius $(\mathrm{ft})$

Output(s)

$t_{d}$: Dimensionless Time (dimensionless)

Formula(s)

$$ t_{d}=\frac{0.0002637 * k * t}{\phi * \mu * c_{t} * r_{w}^{2}} $$

Reference(s)

Lee, J., Rollins, J. B., \& Spivey, J. P. (2003). Pressure Transient Testing (Vol. 9). Richardson, Texas: Society of Petroleum Engineers, Page: 8.