Dehydration Characteristics And Mechanism Analysis Of Crude Oil Emulsion Under The Synergistic Action Of Multiple Physical Fields

Crude oil dehydration is an important link that can not be ignored in the process of oilfield production and transportation,when the total production increases,the produced oil enters the high water cut stage.With the development of extraction technology,alkali,surfactants,and polymers are added to improve the efficiency of oil recovery,resulting in increased viscosity of produced crude oil and serious oil-water emulsification.The single electric field dehydration technology can not achieve the dehydration goal efficiently and stably.Therefore,from the perspective of improving the dehydration efficiency and the final dehydration rate,this thesis carried out the multi physical field combined dehydration technology with electric field as the main and magnetic field as the auxiliary,in order to lay a theoretical foundation for the research of new dehydration technology.In order to explore the dehydration mechanism of crude oil emulsion in electric field and magnetic field,this thesis analyzes the mechanical behavior of water droplets in electric field,the force model of water droplets in the combined field of electric field and magnetic field was established,the layout of electric field and magnetic field was analyzed,and the effect of magnetic field on the motion behavior of water droplets was qualitatively analyzed.Finally,the improvement degree of magnetic field on the dehydration efficiency of emulsion was quantitatively analyzed.In order to verify the combined dehydration mechanism of electric field and magnetic field,the structure and function of the dehydration test platform in crude oil emulsion were designed.It mainly includes the structure,test scheme and process of high voltage power supply device,electric field and magnetic field combined field.The platform can realize the dehydration experiment of emulsion under electric field and magnetic field combined field.According to theoretical analysis and experimental results,the dehydration effect of emulsion increases gradually with the increase of magnetic field intensity,and there is an optimal combination relationship between magnetic field and electric field.In the combined dehydration process of electric field and magnetic field,the dehydration rate of emulsion in the early stage of dehydration is positively proportional to the size of magnetic field,and inversely proportional to the action time of magnetic field,and the dehydration effect of emulsion in the late stage of dehydration is positively proportional to the size of magnetic field and action time.The coalescence characteristics of water droplets are related to the viscosity of emulsion,electric field intensity,magnetic field intensity,particle size of water droplets and other factors,water droplets size and other factors,in the combined field which is dominated by electric field and supplemented by magnetic field,there exists the electromagnetic combined optimal layout,which verifies the correctness and feasibility of the dehydration mechanism theoretically and experimentally,and provides meaningful theoretical guidance for the new electric dehydration technology.