Dynamic Characteristics Of Oil Water Phase In Emulsion Under Electric Field

For the current situation,the development of high water content oil fields,deep-water oil fields,marginal oil fields and green oil fields poses new challenges to the process of oil and gas production and transportation,and the demand for efficient and compact oil electric dehydration technology is increasing.Not only should the technology and equipment of electric dehydration of oil emulsion be constantly updated and broken through,but also the electrostatic coalescence principle of water droplets in the process of electrode hydration of emulsified crude oil needs to be further studied.By comparing the effects of electric field with different parameters on the emulsion,a series of experimental studies on the desulfurization mechanism and the technical performance of crude oil emulsion are carried out.In water in oil emulsion,the conductivity of oil phase and water phase is very different.After the applied electric field,the water droplets can be polarized through the electrostatic field,and the polarized water droplets collide and coalesce under the combined action of electric field and mutual attraction.The process includes migration coalescence and dipole coalescence.Based on the quantitative characterization of the physical and chemical properties of the emulsion to ensure its stability,taking the pre water separation rate as the main evaluation index,the influence on the static demulsification and water separation characteristics of oil in water(O / W)emulsion with volume ratio of 3:7 And 2:3 is planned.In order to further study the microemulsion mechanism of oil in water(O/W)emulsion,the droplet and droplet coalescence in oil in water emulsion were studied.The microscopic model was simulated by COMSOL software,and the rules of influencing factors were summarized.Based on the phase field method,the melting model of droplets in two soluble liquids is established.The results show that when the electric field intensity is large and the included angle,interfacial tension and viscosity of the continuous phase are small,the distance between the two droplets is obvious,and the distance between the completely melted droplets in a short time is different from that between the center of the electric field.Based on the method of horizontal droplet aggregation,the model of horizontal droplet aggregation is established.The results show that with the increase of electric field intensity,the interfacial tension decreases,the viscosity of continuous phase decreases,the volume ratio of secondary droplets to initial droplets increases,and the interfacial aggregation of incomplete droplets increases.In the design of power supply circuit,considering the tracking to improve the performance of static synchronous compensator(STATCOM),a space voltage vector control(SVPWM)method based on the separation of effective current and invalid current in dq coordinate system is introduced.By introducing the city voltage vector modulation technology and coupling the attenuation of active current and reactive current in dq coordinate system,the current command can be tracked accurately and quickly,the switching frequency can be reduced and the utilization rate of DC voltage can be improved.The simulation model based on the control method is established on the MATLAB platform.The simulation results show that the control method can accurately and quickly compensate the reactive power of the power grid,improve the power factor and stabilize the DC side voltage.The system has good dynamic and static performance and has practical application reference value.