Abstract: Emulsion′s stability plays an important role in chemical flooding enhancing oil recovery（EOR）.The strong emul- sion′s stability will make the demulsification more difficult.The weak emulsion will make the demulsification faster and thus impact expanding swept volume.Influences of different kinds of inorganic salt on the stability of emulsions binary flooding system in Xinjiang Oilfield was discussed.It was shown that the inorganic salts effectively accelerated the demulsification of O/W emulsions.Maximum demulsification efficiency by adding bivalent cation was up to more than 100%.The types of anion had little effect for demulsification.It was also found that demulsification efficiency was attributed to valence of cation and Zeta potential.

Key words: binary flooding, emulsication, Zeta potential