Darcy's Law for Linear Single-Phase Flow Calculator
Enter permeability, area, pressure drop, viscosity, and flow length. The calculator returns single-phase volumetric flow rate.
Calculation context and source notes
Darcy's law for linear single-phase flow estimates volumetric flow rate through porous rock from permeability, flow area, pressure drop, viscosity, and flow length.
Use it for reservoir-flow screening, core-flow interpretation, and simple linear-flow checks when single-phase Darcy assumptions are reasonable.
Solves for
q (bbl/day)
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Formula, variables, and sourceRelated source-backed guides
Formula, variables, and default calculation
Reproducible default result
With the default values shown below, the calculation returns q = 2.8175 bbl/day. Defaults demonstrate the implementation; they are not recommended field values.
100
500
100
2
1000
Input definitions
k
mDPermeability
A
ft²Cross-Sectional Flow Area
DeltaP
psiPressure Drop
mu
cPFluid Viscosity
L
ftFlow Length
Output definitions
q
Volumetric Flow Rate
k
Permeability
A
Cross-Sectional Flow Area
DeltaP
Pressure Drop
mu
Fluid Viscosity
L
Flow Length
Engineering use, assumptions, and limits
Use it for reservoir-flow screening, core-flow interpretation, and simple linear-flow checks when single-phase Darcy assumptions are reasonable.
Assumptions
- Flow is single phase, laminar, and governed by Darcy behavior.
- Permeability, viscosity, area, and pressure drop are representative over the flow interval.
- Boundary and geometry assumptions match a linear-flow model.
Limitations
- Does not model multiphase relative permeability, non-Darcy flow, turbulence, or complex reservoir geometry.
- Not a calibrated reservoir simulator or pressure-transient model.
Common mistakes
- Applying the linear equation directly to radial well inflow.
- Mixing permeability, viscosity, and pressure units from different unit systems.
- Ignoring multiphase flow when gas, oil, and water are mobile together.
Source and record status
Source metadata identifies the relationship implemented by the calculator. Check the cited edition, unit basis, and scope against the engineering case before operational use.
Lyons, W.C. 2010. Working Guide to Reservoir Engineering. Darcy equation discussion.
Open source reference