The Study On Biofortification Treatment Technology And Process Of ASP Flooding Produced Water’s Physical Blending

As Daqing oil field enters into the tertiary oil recovery stage, the technology of ASP flooding produced oil has been obtained the widespread application, which produced a large amount of ASP flooding produced water. Due to containing a large amount of surfactatnt and HPAM, it leads to the difficult separation of alkali oil-water and emulsification, the usage of physical and chemical methods will have a difficult treatment for ASP flooding produced water and a high cost. In recent years, the research of biological treatment methods of oilfield produced water goes well, the treatment effect is very good, which greatly reduced the treatment cost of oilfield produced water. In the process of biological treatment of oilfield produced water, microorganism can use some materials produced from oilfield produced water as nutrients for their own growth, and it also degrades macromolecular organic matter into small molecules organic matter, so as to achieve the treatment purpose of ASP flooding produced water in oilfield.In order to reduce the processing difficulty of produced ASP Flooding Produced Water, blending the ASP flooding produced water with polymer flooding produced water, as the reduced blending proportion of ASP flooding produced water, the sedimentation time of the oil content in produced water decrease under100mg/L, while sedimentation efficiency increase. It is advantageous to heighten the effect of oil-water separation, remove suspended substance and decrease the particle diameter median, which is meaningful to reduce the difficulty of water treatment at current technology. It is determined by experiment:the best ratio of physical sedimentation blending of asp flooding produced water and polymer flooding produced water is7:3, when the blending ratio is70%, the sedimentation of blending water is good, the oil content in produced water decrease under100mg/L in8h.The aerobic process of asp flooding produced water’s biological treatment, the packing specifications and filling rate is crucial, which directly affects the final process result, through experimental study:The40%filling rate of suspended packing under2×2specification is the best treatment effect for ASP flooding produced water, the oil content:2.17mg/L in24h, removal rate was99.1%; suspended solids:8mg/L in24h, removal rate was85.2%; surfactant agent:4.2mg/L in24h, removal rate was71.6%; a slightly higher viscosity.This study on biofortification treatment of ASP blending water has divided into two stages: The first stage will blend ASP flooding produced water, weak base ASP flooding produced water and polymer flooding produced water, through biological methods of A/O technology for strengthening process, HRT is48hours. The stable stage for weak base ASP blending water’s processing effect is:oil removal rate was98.20percent, suspended solids removal rate was 91.10%, polymer removal rate was6.70%, surfactant removal rate was52.80%, viscosity removal rate was16.50%, alkalinity, PH and salinity rised slightly, but not rise much, COD removal rate was10.1%. For strong base ASP flooding produced water’treatment effect:oil removal rate was97.30%, suspended solids removal rate was62.80%, polymer removal rate was21.05%, surfactants removal rate was62.5%, viscosity removal rate was8.40%, COD removal rate was49.30%, the PH was slightly lower, and the alkalinity and salinity rise higher.The second stage, on the basis of A/O process, a new process as BESI process between anaerobic process and aerobic process is introduced, the HRT is48hours, to further strengthen the two kinds of blending water, the processing result of stable stage for weak base ASP blending water is:oil removal rate was99.30percent, suspended solids removal rate was96.30%, surfactants solids removal rate raised to70.50%, viscosity removal rate was20%, alkalinity, salinity, PH and polymer raised slightly, COD removal rate was17.60%. For the processing effect of strong base blending water was:oil removal rate was99.40%, the removal rate of suspended solids72.2%, polymer removal rate was8.20%, alkalinity removal rate was5.60%, surfactants removal rate was85.40%, the viscosity removal rate was26.90%, the COD removal rate was43.10%, PH was slightly lower, salinity increased slightly.In the two kinds of blending waters, the processing result of strong base ternary blending water is better than the weak base ternary blending water. Through the improvement of A/O process in the second stage, the new added BESI process to these two blending water has a better result than the A/O process in the first stage, which has important significance for the present study of improving biological treatment of ASP flooding produced water.