Screening And Demulsification Performance Of De-emulsifying Bacteria In The Oily Soil

At present, most of the oil fields are entering the high water-cut stage and the use of various kinds of chemical oil-displacing agent, leading to product from in oil layer is not only crude oil, but more complex emulsion. Pure rest for settlement cannot achieve the requirement of water-oil separation, but the existing chemical demulsifiers are not easy to degrade, cause the pollution to the environment and human.With the development of biotechnology,people turned to the researching of environmental biodemulsifier.Domestic and overseas scholars havehave achieved some progress from a lot of study, ,but it is unusual for studying on rapid screening biodemulsifier method and extraction.Therefore, based on the present achievements and the biological demulsifier's character ,This paper screened strains which can use hydrocarbons as carbon sources to grow from long-term pollution by oil of soil,established de-emulsifying bacteria rapid screening system,and obtained WSJ-3 de-emulsifying bacteria with high dehydrated efficiency and good genetic stability by screening. Bacteria is preliminarily identified as Bacillus subtilis. The best cultivation condition is liquid paraffin and glucose double carbon source medium, pH=7, 37℃temperatureand with 72 hours cultivate time.Effective extracting the WSJ-3 biodemulsifier through fermentation cultivation,ultrasonic and broken ,then centrifugal sedimentation, solvent extraction and drying combined method. Daqing joint standing crude oil demulsification experiments of biodemulsifier and its combined systems have found that WSJ-3 biodemulsifier has higher demulsification rate and clear emerge water,but its demulsification speed is slow, comparing with chemical demulsifier.Blending with biodemulsifier and chemical demulsifier can achieve higher demulsification effect, which shows that there is a synergistic effects relationship between WSJ-3 biodemulsifier and chemical demulsifier. The studies of this paper has a great value in theoretical analysis and practical operation to guide new and high efficient biodemulsifier product development.