Research on Application of Demulsifier for Shanbei Chang 4+5 Crude Oil

Aimed at the difficulty in demusification of crude oil from Shanbei Chang 4+5 oil layer characteristic of high viscosity,high content of asphaltene,the silicon polymer emulsifier WD-56 was screened from 9 kinds of silicon polymer emulsifier via bottle experiments,and the effect of the dosage of WD-56 and temperature on demulsification were investigated and the microstructure of the water-in-oil emulsion was observation during the process of the demulsification.The results indicated that silicon polymer demulsifer WD-56 gave a higher separation of water from water-in-oil emulsion than that of demulsifer Y which was currently widely used in Changqing oil field.The dehydration rate of emulsion was up to 94.26%when adding 100 mg/L of WD-56 at the temperature of 45℃for 2 hours.The mechanism of demulsification was characterized by studying interfacial properties and the chemical structures of the emulsifiers,suggesting that solubility of the demulsifers in the oil phase determined their variations in demulsification efficiencies.