Calculation of Saturation Exponent from Water Relative Permeability Curves of Reservoir Rocks

Abstract

 Saturation exponent is the most important and fundamental concept in considering the electrical properties or the reservoir rocks. It is a dimension less empirical parameter that is determined experimentally from core plugs. This parameter is important in investigation of hydrocarbon saturation of the oil reservoirs. The value or the saturation exponent depends on the wetting properties of the rock.
Laboratory methods of determining saturation require measurements or electrical resistivities or the rock at partial saturation. In these measurements, saturation anomalies or end effect can be ascertained. Experimental results show side discordance and it is known that difflcultles are encountered which result from a lack of electrical contact between the electrode rings and the fluid network in the core pore space.
Based on the analogy between the electrical and physical properties of the reservoir rocks this paper presents a simple correlation for the estimation of the saturation exponents from water relative permeability curves that are widely available.
Comparisons between values of saturation exponent obtained experimentally and the resultant correlation of the present work have shown a good agreement for most of the samples.