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The effect of the capillary number and its constituents on two-phase relative permeability curves

Conference · · Soc. Pet. Eng. AIME, Pap.; (United States)
OSTI ID:5361883

The goal of this study is to determine the effect of the capillary number on two-phase (oil-water) relative permeability curves. Specifically, a series of steady-state relative permeability measurements were carried out to determine if the capillary number causes changes in the two-phase permeabilities or if any one of its constituents, such as flow velocity, fluid viscosity, or interfacial tension, are the controlling variables. For the core tests, run in fired Berea sandstone, a Soltrol 170 oil-calcium chloride brine-isopropyl alcohol-glycerin system was utilized. Alcohol was the interfacial tension reducer and glycerin was the wetting phase viscosifier. The non-wetting phase (oil) relative permeability showed little correlation with the capillary number. As the interfacial tension decreased below 2.0 dynes/cm, the oil permeability increased dramatically. However, as the wetting phase viscosity increased, the non-wetting phase demonstrated less ability to flow. For the wetting phase (water) relative permeability, the opposite capillary number effect was shown. For both the tension decrease and the viscosity increase, i.e., a capillary number rise, the water permeability increased, but not as much as with the oil curves. No velocity effects were noted for the range studied. A relative permeability model was then developed from the experimental data, based on fluid saturations, interfacial tension, fluid viscosities, and the residual saturations, using regression analysis. The applicability of these regression models were then tested with the aid of a two-phase reservoir simulator.

OSTI ID:
5361883
Report Number(s):
CONF-8310121-
Journal Information:
Soc. Pet. Eng. AIME, Pap.; (United States), Journal Name: Soc. Pet. Eng. AIME, Pap.; (United States) Vol. SPE12170; ISSN SEAPA
Country of Publication:
United States
Language:
English