| Awb | area of wellbore, feet |
| B | formation volume factor, RB/STB |
| cf | formation compressibility, psi–1 |
| ct | total compressibility, psi–1 |
| cwb | compressibility of wellbore fluid, psi–1 |
| C | wellbore storage coefficient, bbl/psi |
| CD | dimensionless wellbore storage coefficient |
| h | reservoir or formation thickness, feet |
| k | permeability, md |
| m | slope of MTR straight line |
| Δp | pressure change |
| Δp′ | pressure change derivative |
| p′D | dimensionless pressure derivative |
| p | pressure, psia |
| pD | dimensionless pressure |
| pwf | well bottomhole flowing pressure, psia |
| pws | shut-in bottomhole pressure, psia |
| q | volume flow rate, STB/D |
| rw | wellbore radius, feet |
| s | skin factor |
| Δt | shut-in time in buildup test, hours |
| Δte | Agarwal equivalent time |
| t | time, hours |
| tD | dimensionless time |
| tp | total producing time before shut-in, hours |
| Vwb | volume of wellbore, barrels |
| φ | porosity, fraction |
| μ | fluid viscosity, cp |
| ρwb | density of fluid in wellbore, lbm/ft3 |
