Study On The Effect Of Oil-water Separation Characteristics Of ASP Produced Water Mixed With Polymer Flooding

Alkaline-surfactant-polymer (ASP) flooding technology is a kind of new technology which has been developed in recently years, and which make important contribution for enhance oil recovery (EOR). A large amount of produced water produced in the process of ASP flooding.ASP flooding produced water is complex and difficult to treat, contains much polymer, alkali and surfacta. The problem of produced water treatment restrain the application of tertiary oil production technol. This article based on the produced water recycling, recycled the ASP produced water after mixed it with polymer flooding produced water, and study on the variational laws of ASP produced water mixed with polymer flooding produced water. Analyze the separation properties of mixed produced water. This article has guiding value for improved the process of ASP produced water treatment.The analysis of water quality showed that ASP flooding produced water has high alkalinity,salinity, polymer concentration and viscosity. The alkali content is about 4959?6261mg/L. Total salinity of wastewater is about 8000-8500mg/L and assumed an obvious increase. Sewage viscosity at 1.1 ?3.75 m Pa·s.The polymer concentration was 421 ?960mg/L. The change of the viscosity of the sewage and the change of the polymer did not show a significant linear relationship. Sulfide content is higher.The water quality of each station with time fluctuations,and the peak value can reach several times much than average value.The mixing experiments indicated that after the prorata admixture, the change of polymer,alkalinity and oil content has no effect. The surfactant content increased with the mixed proportion of ASP flooding produced water. The results of the experiment were lower than the theoretical value. Along with the increase of the proportion of ASP flooding produced water samples, the error of the calculated value is gradually reduced. The viscosity values increased with the mixed proportion of ASP flooding produced water, but the difference between the calculated value and the fluctuation is large. With the increase of the mixed proportion of ASP flooding produced water, the error decreases gradually. After high concentration of ASP flooding produced water and ordinary sewage containing polymer mixed, low concentration polymer and medium concentration of ASP flooding produced water mixed the oil / water separation effect is obviously improved. The oil/water separation characteristics improvement of high polymer, and high viscosity of asp flooding produced water mixed with polymer flooding water got worse.After 12h, different mixing ratio of residual oil content is higher than 100 mg/L.When the polymer concentration is lower, the oil droplet coalescence performance is good,produced water stability got worse. The higher the concentration of polymer is, the higher viscosity of bulk and Zeta potential. The oil droplets coalescence effect is weakened, the stability of water production increased. Variation of the surface active agent have a great influence on water oil-water separation effect. When the surfactant concentration increased, the Zeta potential of oil in the water is increased, the particle size of the oil beads is reduced and the oil droplets coalescence effect is weakened. Alkalinity changes impact on the produced water oil-water separation efficiency is low. The initial oil content and the increase of salinity is helpful for oil/water separation efficiency improvement of asp flooding produced water. Adequate strength mechanical mixing is helpful for the improvement of oil-water separation effect of the mixed water.