Demulsification of Crude Oil Emulsion via Ultrasonic Chemical Method

Abstract

Lots of water and surfactants are poured into the oil well to enhance the exploiting efficiency, so the crude-oil emulsions exploited by this technology contain much water, which is very hard to be separated at present. The demulsifying and separating experiments of the crude-oil emulsion were conducted by using the thermal chemical method and the ultrasonic chemical method separately. The crude oil emulsion samples were provided by the Dagang oil field of China and the water content was 35% volume/volume (v/v). The key influencing factors on demulsification effect were explored by changing the ultrasonic output power, the irradiating time, and the demulsifier amount in the experiments. The dehydrating ratios were compared among the self-made emulsions of different water content with the ultrasonic chemical method. The demulsifying velocity and dehydrating ratio for the high water content crude-oil emulsion was better than that of the emulsion with lower water content in the demulsifying experiments with the ultrasonic chemical method. For the crude-oil emulsion used in this experiment, the result was a dehydrating ratio of 97.7% under the condition of 100 W of ultrasonic output power, 10 min of irradiating time, 50 mg/L of demulsifier, and 75°C of water bath temperature.