Permeability Converter

Permeability measures how easily a fluid flows through porous material. 1 Darcy ≈ ability of water to flow through a sand filter.

Common Permeability Conversions

FromTo
1 Darcy9.8692×10⁻¹³ m²
1 mD (millidarcy)9.8692×10⁻¹⁶ m²
100 mD0.9869 Darcy

Permeability Unit Definitions

Darcy (D)
CGS unit named after Henry Darcy.
Millidarcy (mD)
Common in petroleum engineering.
Square meter (m²)
SI unit of permeability.

Frequently Asked Questions

What permeability is considered good for an oil reservoir?

Typically 10–10,000 mD. Below 1 mD is considered tight; shale formations can be <0.001 mD, requiring hydraulic fracturing.

How does permeability differ from porosity?

Porosity is void space volume fraction; permeability measures how connected those voids are for flow. High porosity does not guarantee high permeability.

What is Darcy's law?

Darcy's law: Q = -kA(dP/dx)/µ, where Q is flow rate, k is permeability, A is area, dP/dx is pressure gradient, and µ is fluid viscosity. Permeability in SI units is m².