Study On Influencing Factors And Stability Of Emulsifying And Reducing Viscosity Of Heavy Oil In

The heavy oil from Xinjiang Ji7district is difficult to be produced, transported and high-energy-consumed due to its high viscosity. After reviewing commonly used methods of the viscosity and drag reduction of heavy oil, the emulsification method is recommended as the most prospective one. Therefore, it is necessary to do a systematic research on the factors affecting the viscosity reduction and stability of Ji7heavy oil in water emulsion.This paper adopted BSY-338wax, resin and asphaltene content analyzer for crude oil to analyze the contents of three components for Ji7heavy oil. Rheolab QC viscometer and its temperature controller were adopted to analyze the rheological properties, relation of viscosity and temperature, and wax appearance temperature. KD-R1000condensation point-pour point test instrument was adopted to test the condensation point of Ji7heavy oil. Based on the related studied data,2kinds of cationic surfactants,3kinds of anionic surfactants and4kinds of nonionic surfactants were selected for further evaluation. Based on the viscosity reduction evaluation, factors such as water content, emulsifier concentration, stirring rate and emulsification temperature were investigated for the effects on rheological properties of emulsions. Settling method was adopted to evaluate the static stabilities of O/W emulsions, and temperature, stirring rate and inorganic salt content were investigated for the effects on them. Rotational rheometer, stirring method and simulative loop pipe were adopted to evaluate the dynamic stabilities of O/W emulsions. Viscosity reduction through emulsification was validated for its feasibility in Ji7district. The field application plan of Ji7heavy oil emulsification and viscosity reduction was specialized.The experimental results show that Ji7crude oil belongs to commonly heavy oil due to its viscosity of524.5mPa·s at50℃and density of928.95kg/m3at20℃. Its condensation point is12℃and wax precipitation point is34℃. Its phase inversion point lies between50%～60%of water content. Surfactant OP-10acts better than other surfactants, and it acts best at30%of water content as well as0.7%of its concentration.20%of water content or lower surfactant concentration cannot prepare a stable O/W emulsion. During the preparation of an emulsion, surfactant solution temperature affects more on its structure and rheological property than oil temperature. If the temperature of the emulsion is lower than the surfactant cloud point, with the temperature increasing, the stability becomes worse. With the stirring rate increasing in a certain range, the stability becomes better. The viscosity reduction rate of Ji7heavy oil made though flowing inside the pipe is as high as85%. A screw pump pumps the Ji7heavy oil of13.85L/min at most in the vertical pipe loop, however, it can pump21L/min mixture of oil and water at the water content among30%～40%. These results not only lay a theoretical foundation for the technical development of the economic and efficient exploitation and transportation of Ji7heavy oil, but also perform a demonstration for similar heavy oil blocks.