Study Of Bio-demulsiifer For Contained Polymer Crude Oil Emulsion

Polymer flooding produced fluid demulsification was one of hot difficulty questions formany domestic oil fields. Traditional chemical demulsifier was hard reached satisfactoryoil-water separation effect, even increased the amount of chemical demulsifier.Bio-demulsifier have high demulsification efficiency and wide application range thanchemical demulsifier, so it enchanted by many researchers.This paper searching aPseudomonas sp bio-demulsification strain. Medium composition of the bio-demulsificationbacteria culturing was studied. The culture condition effect of bacteria growing and polymerflooding emulsion demulsification capability was systematic investigated. Batch fermentationkinetics model was established.This article mainly provide reference for polymer floodingemulsion bio-demulsifier development.This paper studied nutrition composition of bio-demulsification bacteria strain medium,investigated different kind of carbon, nitrogen, phosphorus sources in medium and C/N effectfor bio-demulsification bacteria growing.Through response surface method optimizedmedium composition. The results showed that bio-demulsification bacteria had various cellratio with different kind of carbon or nitrogen sources, cell ratio sequence from high tolow:mixed carbon source(glucose and liquid paraffin)＞glucose＞soluble starch＞lactose＞liquid paraffin,NH4CL＞mixed nitrogen (NH4CL and yeast extract)＞mixed nitrogen(NH4NO3and yeast extract)=mixed nitrogen (NaNO3and yeast extract)=NH4NO3=NaNO3,NO3-could inhibit bio-demulsification bacteria growing when it as nitrogen sources.Thebio-demulsification bacteria growth rapidly increased at first and then slightly decreased withthe increase of C/N, it reached max value when C/N was five. Mixed phosphorus sources(K2HPO4and KH2PO4) could increase bio-demulsification bacteria growing then singlesource(K2HPO4or KH2PO4) when phosphorus sources concentration in the range of0～10g/L. The bio-demulsification bacteria growth increased at first and then decreased with theincrease of K2HPO4/KH2PO4(mass ratio), it reached maximum value when K2HPO4/KH2PO4was1:1. We could learn through response surface method that bio-demulsificationbacteria could reach maximum growth when K2HPO4/KH2PO4was1.38, C/N was5.1andliquid paraffin content was4.1%(v/v).The influence of different culture conditions on the bio-demulsification bacteria growingand the de-emulsification capability, which include initial pH value, inoculation amount,incubation temperature and shaker revolution, was investigated in this paper, and also, a batchfermentation kinetics model was established. The results showed that bio-demulsification bacteria could obtain maximum growth when the culture condition as following: shakerrevolution speed is at140r/min; initial pH is8.0; culturing temperature is25℃andinoculation amount is4%.Inoculation amount is little effect for bio-demulsification bacteriade-emulsification capability, bio-demulsification bacteria could obtain maximumde-emulsification capability when the culture condition as following: shaker revolution speedis at140r/min; initial pH is9.0; culturing temperature is30℃. Based on the equations ofLogistic and Luedeking-Piret, the kinetics models describing bio-demulsification bacteriagrowing and glucose consuming were established, the models could well fitting the situationof bio-demulsification bacteria growing and glucose consuming.