The Study On ABR Biological Treatment Efficiency Of ASP Flooding Produced Water

Now Daqing oil field enters into the tertiary oil recovery stage, as the technology of ASP flooding produced oil has been obtained the widespread application, a large number of asp flooding produced water has been produced. The composition of oilfield ASP flooding waste water is very complex which is including crude oil, suspended solid, polymer, alkaline, surfactant and some chemicals, etc. Due to containing a large amount of chemicals, it leads to the difficult separation of oil-water and emulsification, it is also difficult for the conventional physical and chemical methods to have a high efficiency treatment for ASP flooding produced water but cost much. Based on the above situation the study of biological treatment of oilfield produced water has been produced, it has a good treatment effect and low processing cost at same time. The principle of biological treatment of oilfield produced water is that microbes can use some organic material which in the asp flooding produced water as nutrient substrates for their growth, and catabolism them in their growth so as to achieve the treatment purpose of ASP flooding produced water in oilfield.In order to remove the pollutants and chemicals contaminant in oilfield ASP flooding waste water, we used the anaerobic baffled bioreactor (ABR) to deal with the waste water. The hydraulic retention time (HRT) from the 72 hours reduced to 24 hours in 30 days of domestication process, and the ABR bioreactor purification ability gradually improved and the bioreactor became stable. Low alkali-type ASP produced water after 100 days of treatment, the results showed that the oil removal rate reached 99.80%, the suspended solid removal rate reached 94.40%, the of polymer removal rate reached 7.00%, the viscosity decreased 20.00%, the surfactant removal rate reached 50.00%, the total alkaline removal rate reached 16.00%;High alkali-type ASP produced water after 60 days of treatment, the results showed that the oil removal rate reached 98.50%, the suspended solid removal rate reached 96.50%, the of polymer removal rate reached28.80%, the viscosity decreased 20.00%, the surfactant removal rate reached 62.30%, the total alkaline removal rate reached 34.80%;Wellhead low alkali-type ASP produced water after 30 days of treatment, the results showed that the oil removal rate reached 99.20%, the suspended solid removal rate reached 89.50%, the of polymer removal rate reached 21.90%, the viscosity decreased 30.40%, the surfactant removal rate reached 53.80%, the total alkaline removal rate reached 15.50%.Northwest 2 Low alkali-type ASP station produced water after double cylindrical filter reactor treatment the suspended solid content dropped to 25.60mg/L, oil content dropped to 3.5Omg/L, and the effect well be better if poly aluminium chloride has been used in raw water pretreatment.