Abstract: A novel polyquaternary ammonium reversed demulsifier was synthesized with Jeffamine D-230, epichlorohydrin and N, N-dimethylethanolamine as raw materials. According to the molar ratio of Jeffamine D-230 to epichlorohydrin (1:2 and 1:4), The synthesized products with n(D-230)/n(epichlorohydrin)=1:2 and 1:4 are named Y-562 and Y-564,respectively. They were evaluated by bottle test with fresh crude oil from a petroleum platform in Bohai. The results indicated that when the demulsification temperature is 70℃, the demulsification time is 20 min and the amount of Y-564 is 15 mg/L, the water content in the oil is 0.7% and the amount of oil in the water is 80mg/L. The water layer in lower part is clear and the oil and water interface is clear, it means to achieve the optimum dehydration effect.

Key words: polyquaternary ammonium, Reversed demulsifier, oil in water emulsion