Effects of alkaline flooding on the recovery of Safaniya crude oil of Saudi Arabia

The effects of three types of alkalies on recovery of Safaniya crude oil of Saudi Arabia from sandpacks were studied. The three alkalies used were sodium hydroxide (NaOH), potassium hydroxide (KOH), and sodium phosphate (Na3PO4·12H2O). The effect of the alkalies in polysaccharide solution was also studied. The polymer concentration was 1000 ppm. Three physical properties of the alkaline solutions were measured: the pH value, viscosity, and interfacial tension. Results showed that the highest recovery of oil was obtained by using the NaOH solution. This was due to the high pH value and lowering of interfacial tension between the oleic and the aqueous phases. comparing the displacement results of the alkaline solutions with the displacement results of the alkalies in polymer solution, it was found that the higher oil recovery of Safaniya crude oil could be obtained by displacement of oil by alkali in polymer solution.