Permeability

Introduction

For oil, gas, or groundwater to be able to get into a rock with good porosity it must also have good permeability. For a rock to be permeable and for water to move through it, the pore spaces between the grains in the rock must be connected. Permeability is therefore a measure of the ability of water to move through a rock.

For multiphase flow scenarios, refer to Relative Permeability.

For directional permeability scenarios, refer to CSG Permeability / Permeability Anisotropy or just Permeability Anisotropy

The definition of permeability is based on an empirical correlation developed by French Engineer Henry Darcy. In 1856, Darcy conducted an experiment where water was allowed to flow through a porous sand bed under a known hydraulic head. The flow rate of water was found to be proportional to the hydraulic head of water. The constant of proportionality is known as the hydraulic conductivity of the porous medium.
Mathematically, the hydraulic conductivity of a porous medium between points 1 and 2 can be expressed as follows:

Where: q = volumetric flow rate K = Hydraulic conductivity A = Cross-sectional area to flow dh = Difference in hydraulic head between points 1 and 2.

Conventional vs Unconventional Permeability

See Also

References

• Victorian State Government: Department of Energy, Environment and Climate Action (DEECA)

• Satter & Ghulam, Reservoir Engineering The Fundamentals, Simulation, and Management of Conventional and Unconventional Recoveries, 2016.