A Study On Biodemulsifier

When all kinds of methods for enhancing oil recovery are used in oilfield, much surfactants needs to be added to displacing fluid,so that produced emulsion is stable and difficult to be separated, can not be demulsified by common chemical demulsifier. Moreover, the existing chemical demulsifier is not environmental protection, homininoxious and so on, which conflicts with HSE safety management model at present. Therefore, environmental biodemulsifier is attracting increasingly more attention.Biodemulsifier, a high surface-active agent synthesized by microorganism, is environmental and easily biodegradation material,the domestic and oversea scholars have achieved some progress from a lot of study, but it is unusual for studying on rapid screening biodemulsifier method and synergetic effect. Therefore, based on the present achievements, by using crude emulsion breaking physical simulation experiments and instrumental analysis techniques,biodemulsifier rapid screening method, evaluation method and the environmental factors that affect biodemulsifier producing and demulsifying ability are researched from macro and micro ways,the demulsification of biodemulsifier compound system on produced liquid from Daqing Oilfield is analyzed by comparison. The research result indicates that, combined with oil plate and blood plate methods,biodemulsifier rapid screening system that is adapted to the environment can be established.PDR biodemulsifiers with high dehydrated efficiency obtained by screening are numbered from PDR-1 to PDR-4,which are preliminarily identified as Bacillus subtilis.The living environment with 40℃temperature, pH=7,150r/min vibration is the best, when concentration is 300mg/L, the dehydrated efficiency of PDR-2 with better adaptability to environment, is up to 87% in 24h, and under fluid appears grossly clear after emulsion breaking.The comparison experiments of PDR-2 biodemulsifier and chemical demulsifier shows that, the demulsification activity of biodemulsifier is lower than that of chemical demulsifier within 24h, but biodemulsifier takes effect in a long period and predominate latterly, the dehydrated efficiency of PDR-2 biodemulsifier compound system with the scale of 1:3 is higher, and can reach 99% within 24h, which shows that there is an obvious synergistic effects relationship between biodemulsifier and chemical demulsifier. The research has a great value in theoretical analysis and practical operation to guide new and high efficient biodemulsifier product development.