# Relative permeability from unsteady-state displacements with capillary pressure included

## Abstract

A semianalytic method for calculation of relative permeabilities from unsteady-state displacement data is developed. The method is based on the simultaneous solution of the fractional-flow equation and an integro-differential equation, derived from the material-balance and Darcy equations for immiscible displacement of two incompressible phases, including the capillary pressure by use of various volumetric relationships. This method for calculating two-phase relative permeabilities from unsteady-state displacement data is not restricted to the high-flow-rate experimental conditions used to overcome capillary and effects. Removal of this restriction allows the analysis of low-permeability cores with water and oil where the flow rates are low and capillary end effects are important. Our method allows direct calculation from the experimental data without intermediate interpretations of graphs.

- Authors:

- Publication Date:

- Research Org.:
- Oklahoma Univ., Norman, OK (USA). School of Petroleum and Geological Engineering

- OSTI Identifier:
- 5791606

- Resource Type:
- Journal Article

- Resource Relation:
- Journal Name: SPE (Society of Petroleum Engineers) Format. Eval.; (United States); Journal Volume: 4:2

- Country of Publication:
- United States

- Language:
- English

- Subject:
- 02 PETROLEUM; 03 NATURAL GAS; RESERVOIR ROCK; PERMEABILITY; CALCULATION METHODS; DARCY LAW; DATA ANALYSIS; DIFFERENTIAL EQUATIONS; DISPLACEMENT FLUIDS; FLUID FLOW; INCOMPRESSIBLE FLOW; TWO-PHASE FLOW; WELL PRESSURE; EQUATIONS; FLUIDS; RESERVOIR PRESSURE; 020200* - Petroleum- Reserves, Geology, & Exploration; 030200 - Natural Gas- Reserves, Geology, & Exploration

### Citation Formats

```
Civan, F., and Donaldson, E.C..
```*Relative permeability from unsteady-state displacements with capillary pressure included*. United States: N. p., 1989.
Web. doi:10.2118/16200-PA.

```
Civan, F., & Donaldson, E.C..
```*Relative permeability from unsteady-state displacements with capillary pressure included*. United States. doi:10.2118/16200-PA.

```
Civan, F., and Donaldson, E.C.. Thu .
"Relative permeability from unsteady-state displacements with capillary pressure included". United States. doi:10.2118/16200-PA.
```

```
@article{osti_5791606,
```

title = {Relative permeability from unsteady-state displacements with capillary pressure included},

author = {Civan, F. and Donaldson, E.C.},

abstractNote = {A semianalytic method for calculation of relative permeabilities from unsteady-state displacement data is developed. The method is based on the simultaneous solution of the fractional-flow equation and an integro-differential equation, derived from the material-balance and Darcy equations for immiscible displacement of two incompressible phases, including the capillary pressure by use of various volumetric relationships. This method for calculating two-phase relative permeabilities from unsteady-state displacement data is not restricted to the high-flow-rate experimental conditions used to overcome capillary and effects. Removal of this restriction allows the analysis of low-permeability cores with water and oil where the flow rates are low and capillary end effects are important. Our method allows direct calculation from the experimental data without intermediate interpretations of graphs.},

doi = {10.2118/16200-PA},

journal = {SPE (Society of Petroleum Engineers) Format. Eval.; (United States)},

number = ,

volume = 4:2,

place = {United States},

year = {Thu Jun 01 00:00:00 EDT 1989},

month = {Thu Jun 01 00:00:00 EDT 1989}

}