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Relative Permeability Correlations

Two-Phase Correlations

In a two-phase system, the fluids consist of oil and water, oil and gas, or gas and water. An example of an oil-water system is shown below:

Corey

This model assumes the wetting and non-wetting phase-relative permeabilities to be independent of the saturations of the other phases and requires only a single suite of gas / oil-relative permeability data.

Water / Oil System

Gas / Oil System

Gas / Water System

Honarpour

Developed using data from oil & gas fields in the continental US, Alaska, Canada, Libya, Iran, Argentina and the United Arab Republic.

Sandstone

Water Wet

Intermediate Wet

Any Wettability

Limestone

Water Wet

Intermediate Wet

Any Wettability

Generalized Corey

Similar to the Corey correlation, but developed for a wider range of rock and wettability characteristics. This correlation can be used to change the endpoints of water-oil and gas-liquid relative permeability curves while still retaining the shape of the curves.

Gas / Oil System

Gas / Water System

Water / Oil System

Three-Phase Correlations

Three-phase relative permeability can be generated from the two-phase relative permeability curves of the oil-water system and the relative permeability curves of the gas-oil system. The two-phase curves represent the end curves when either the gas saturation or water saturation equals zero.

Stone I

This probability model estimates three-phase permeability data from laboratory measured two-phase data. It uses the channel flow theory in porous media to obtain a simple result for determining the relative permeability to oil in the presence of water and gas flow. The model implies that water-relative permeability and water-oil capillary pressure in three-phase systems are functions of water saturation alone, irrespective of the relative saturations of oil and gas. Similarly, the gas-phase relative permeability and gas-oil capillary pressure are the same functions for gas saturtion in the three-phase system as in the two-phase gas-oil system.

Stone I is widely used in the industry as the benchmark for oil simulation. It is a better predictor than Stone 2 in low oil saturation regions, is more appropriate for water-wet systems, and is not suited for intermediate wet systems.

Stone II

Stone's Model II is a modified version of Stone I. It is a better predictor than Stone 1 in high-oil saturation regions. It is more appropriate for water-wet systems and is not suited for intermediate wet systems.

Baker

Baker's three-phase model is based on saturation-weighted interpolation between the two-phase relative permeability values. It is well suited for intermediate wet or oil-wet systems.

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