PermeabilityEr

Permeability refers to the ability of rock to allow fluid to pass under a certain pressure difference.
It is a parameter to characterize the liquid conductivity of soil or rock itself. Its size is related to porosity, pore geometry, particle size and arrangement direction in the direction of liquid permeation, but not to the liquid properties in the medium. Permeability (k) is used to indicate the size of permeability.
When the pressure gradient is 1, the permeation velocity of the liquid with dynamic viscous coefficient of 1 in the medium. The dimension is L2.
The unit of permeability is the square of length, that is, the same unit as the unit of area. But we call it Darcy (D), and the commonly used unit is millidarcy (md).
Permeability is the physical basis of oil (gas) reservoir rocks. It is the basic data for both oil and gas migration and accumulation and oil (gas) field development. However, their values vary greatly in different oil (gas) formations. From several millidarcy (md) to thousands of millidarcy (md).