The Characteristic Of Electrocoalescence Of ASP Flooding Production

The ASP flooding, is a method applied to tertiary oil recovery. However, the drugs remained in the production make the process of demulsification more difficult. Therefore it is hard to separate the oil phase and the water phase. This paper uses a homemade electrocoalescence experiment system including the high speed video with the microscope objective and the VIEC device to observe the motion, deformation and coalescence of micron-scale droplets containing different concentration of drugs under different electric fields and the laws that how the concentration and the electric field parametres effect the electrocoalescence of droplets. The main contents and conclusions of research are following.The researches of droplet deformatin find out that with increasing of the single alkali concentration or decreasing of the single surfactant concentration, the water droplet deformation degree increases firstly and decreases afterward; with increasing of the single polymer concentration the water droplet average eccentricity changes as a W-curve.When the concentration of alkali is a constant, with increasing of the surfactant and polymer concentration, the deformation degree decreases firstly and increases afterward; When the concentration of surfactant is a constant, with increasing of the alkali concentration, the deformation degree decreases and with increasing of the polymer concentration,it increases firstly then decreases; When the concentration of polymer is a constant, with increasing of the alkali concentration, the deformation degree decreases then unchangs and with increasing of the surfacant concentration, it increases firstly then decreases and finally increases again. In the interaction of three drugs, with increasing of the surfacant concentration, it increases firstly then decreases and finally increases again; with increasing of the polymer concentration, it decreases firstly then increase; with increasing of the alkali concentration, it stays between 0.26 and 0.32.It finds out that the average eccentricity of the drop with ASP flooding in the sinusoidal alternating electric field is directly proportional to the field strength with a power of N(N>1). Under the sinusoidal electric field, with different polymer concentration, the deformation degree increases as the electric field frequency increases. With different alkali concentration and the increase of the electric field frequency, the deformation degree decreases firstly and increases afterward. Additionally, with different surfactant concentration and the increase of frequency, there are two peak points with corresponding frequency of 100 Hz and 800 Hz. Under the pulsed electric field, with different polymer or surfacant concentration, the deformation degree increases as the electric field frequency increases; when the frequency below 300 Hz and pH equals 9.5 or 10, it decreases firstly then increase, but when pH equals 10.5, it increases as frequency increases,when the frequency above 300 Hz, it is a constant.The deformation degree increases as the duty ratio increases.The research on the water movement velocity shows that, the droplet velocity decreases first and then increases with the increase of the concentration of surface active agent and pH value; the droplet velocity increases first and then decreases with the increasing polymer concentration.When the duty ratio is 50%, the electric field intensity is 500kV/m, or the electric field frequency is 500 Hz, the water droplets reach the maximum velocity.The study on the liquid film thinning rate between droplets found that when the rate reaches the maximum in the sinusoidal AC electric field, the polymer and surfactant concentration are 400 ppm and 20ppm; and the liquid drainage rate remains almost unchanged with the increase of the alkali concentration.In the pulse electric field, the trend of dual droplets changes with the three component concentration is basically the same. But for the water contains alkaline, its drain rate faster under the effect of impulse electric field.The critical coalescence field strength of the dual droplets in the emulsion with 10% water content can be obtained by using the conversion formula: Ec=2475e-d/20+200, where D is the effective radius, μm; Ec is the electric field strength, kV/m.From the experiment data, we find that if we improve the electric field intensity, coalescence effect of droplets increases. But we also find that droplet size in white oil(moisture content is 20%.) changes smaller. Add alkali, surfactant and polymer into emulsion in turn, then coalescence effect and separation efficiency will change smaller. orthogonal experiments tell us that drops coalescence effect, water and energy consumption will be affected if aqueous solution which contain alkali, surfactant and polymer change into W/O emulsion. Significant effect on the droplet coalescence performance from high to low in turn is alkali, surfactant, polymer, waveform. If moisture content and frequency is different, Significant effect on sedimentation water and energy consumption performance from high to low in turn is alkali, surfactant, polymer. Significant effect is less in the low frequency than which in the high frequency. When three chemicals content change, the square wave which owns better adaptability suit for the volatile situation of the nature of the water.