Experimental Study of the Effect of Salinity and Relative Permeability on Water flooding Case Study: X Sudanese Oil Field

Abstract

Water flooding is the most widely used technique in secondary recovery methods in the oil industry that can affect any reservoir when applied it the efficiency of improvement of the recovery on the reservoir when water flooding is applied depend many parameters. The objective of this study is to study and evaluate the relative permeability and analyses the effect of salinity in water flooding and calculation the recovery factor of the oil producing in sandstone reservoir. Recent studies showed that salinity concentration of the injection is more important factor rather the amount of water injection. Laboratory experiment had been carried to determine the recovery factor by using three sandstone core samples. four different concentrations of salinity 35*1000 ppm, 25*1000 ppm ,10*1000 ppm and 1.044*1000 ppm, respectively. was used in water flooding for the core samples. Based on the results obtained, the highest total recovery by water flooding was 4.699% with 1.044*1000 ppm salinity, it also showed that oil recovery is increase when concentration of the salinity decrease. Obtaining accurate relative permeability curves from core-flood experiments is imperative for characterizing a reservoir and for estimating its production capability. This paper is concerned with the unsteady-state relative permeabilities that are obtained from water-flood experiments conducted in a water-wet medium. The effect of relative permeability on oil recovery was studied by using a base flood by formation water (FW) for each core. Injection was continued at constant rate, pressure drop was continually monitored, and cumulative production of displacing fluid was measured as a function of time. Relative permeability of each phase was calculated independently with the JBN method. The results gave recovery factor between 44-56% from the samples.