Permeability Converter — Darcy, Millidarcy, m²
Convert between 5 units of permeability — m², cm², Darcy (D), millidarcy (mD), and microdarcy (μD). Permeability describes how easily fluid flows through porous rock or soil. Clean gravel has permeability of ~1 Darcy; tight shale reservoirs can be as low as 0.001 mD. Named after Henry Darcy (1856). Used in petroleum engineering, groundwater hydrology and filter design.
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About the Permeability Converter
Permeability in fluid mechanics describes how easily a fluid can flow through a porous material such as rock, soil, or a filter membrane. The Darcy (D) is the practical unit — named after Henry Darcy who formulated the law of fluid flow through porous media in 1856. Reservoir engineers use millidarcy (mD) to characterise oil and gas formations. One Darcy ≈ 9.869 × 10⁻¹³ m².
Quick facts
- ›Clean gravel has permeability of ~1 Darcy; tight shale reservoirs can be as low as 0.001 mD (nanodarcys)
- ›Hydraulic fracturing (fracking) increases rock permeability to make low-permeability reservoirs productive
- ›Membrane filters for water purification are rated by their effective pore size related to permeability
- ›Henry Darcy published his permeability law in 1856 based on experiments with sand-filled pipes
Common uses: Petroleum engineering, hydrogeology, soil science, filtration, civil engineering