Permeability in Geology

A method for measuring relative permeability where the oil flow rate is kept constant to create a desired pressure drop, then lowered while another fluid (oil or water) is injected to keep the pressure drop consistent until equilibrium occurs.

A common method for measuring relative permeability where fluids are injected at a constant rate and fluid volume changes are monitored at the outlet.Relative permeabilities are measured at breakthrough.

Saturation discontinuity at the outflow face of a porous medium during a flow test. Fluid discharge occurs into a non-porous region, causing a saturation gradient at the outflow.

A piece of porous material used to fill any region void of porous material adjacent to a core sample at the outlet, decreasing or removing the end effect.

The process of obtaining relative permeability data by decreasing the wetting phase saturation while injecting a non-wetting fluid.

Obtaining relative permeability data by increasing the saturation of the wetting phase (e.g., water).

Differences in relative permeability measurements when changing saturation history. Data varies depending on whether the wetting phase is being reduced or increased.

The lowest water saturation level possible for oil removal. Beyond this point, water saturation increases and oil is eventually fully displaced.

The state of the wetting phase (water, in this case) forming connected, but small, rings around rock grains in a reservoir.

A state where both wetting and non-wetting phases flow continuously through their own pore networks.

The state where the non-wetting phase (oil, in this case) exists as small, isolated pockets or islands within the reservoir.

A technique using a specialized apparatus to measure the relative permeability of fluids in a porous medium under consistent flow conditions.

A measure of how easily a fluid flows through a porous medium in the presence of other fluids.

The fluid that preferentially wets the rock surface in a porous medium.

The fluid that preferentially resides in the spaces of a porous medium that are not wetted by other fluids.

Permeability of a rock to a fluid when other fluids are present, measured in darcies or millidarcies.

A dimensionless quantity representing the permeability of a fluid phase relative to the total permeability of the rock.

The fluid that preferentially wets the rock in a multiphase system (e.g., water in a water-oil system).

The fluid that does not preferentially wet the rock in a multiphase system (e.g., oil in a water-oil system).

Curves illustrating the permeability of different fluid phases (e.g., water, oil, gas) relative to that of the total rock permeability and saturation levels.

The minimum saturation of the wetting phase that can exist in a porous medium; below this, the wetting phase will not drain away.

Techniques used to determine the permeability of core samples under controlled conditions, often involving measuring pressure and flow rate.