Research On The Demulsification Of Produced Fluids From Chemical Flooding In Liaohe Oilfield

Chemical flooding can improve the oilfield production and exploitation year,and it also increases the difficulty of the subsequent dehydration for produced fluid.From the results of pilot testing for surfactant-polymer flooding in Liaohe Oilfield,the increasing of the concentration of polymer and surfactant can lead to serious oil-water emulsification and exceeding standard of water content in crude oil after dehydration.It is necessary to study the stability and emulsification properties,so that can provide theoretical support for the exploitation of chemical flooding in Liaohe Oilfield.On the basis of the determination of physical properties for produced liquid from chemical flooding,preparation condition for simulated emulsion have been determined through "Three-Similar Principle.The influence of oil-displacing agent for dehydration,apparent viscosity,the micro particle size and the interfacial properties of produced liquid has been studied.Experimental result show that different oil displacement agent have different effects on the stability of emulsion,petroleum sulfonate enhance the stability of the emulsion mainly by reducing the oil-water interfacial tension and polymer can also enhance the stability of the emulsion mainly by reducing the oil-water interfacial tension.In addition,related degree between different indicators and the stability of the emulsion has been determined by using grey relational theory,the experimental results show that interfacial shear viscosity has the highest correlation degree with stability of the emulsion.The influence of demulsifier for dehydration,interfacial properties and microstate of produced liquid are studied,and then the properties that demulsifier effects on produced fluid is discussed,the best dehydration parameters for produced liquid form chemical flooding in Liaohe Oilfield is selected through orthogonal test.At last the influence of electric field type,oil displacement agent,water volume fraction,temperature and demulsifier for dehydration are analyzed,and then the characteristics of electric dehydration for produced fluid from chemical flooding is discussed.