The Studies On Emulsification Process Of Chemical Flooding

Chemical flooding EOR process, the mechanism of emulsification flooding is oilemulsifying and emulsion profile controlling. Study the conditions of making crude oil–wateremulsion and its stability factors. Explore the formation of emulsion of chemical flooding andthe mechanism of emulsification. Both of them have important meaning for improving thechemical flooding recovery.By means of diphasic titration and ultraviolet spectrophotometer, the changes in contentof surface active agents in aqueous emulsion with time allocation were studied. The resultsshowed that the time that surface active agents at oil-water interface reached adsorptionequilibrium during the emulsification process was2h. Compared with the emulsifyingproperties of ternary systems of petroleum sulfonate+weak base (Na2CO3)+HPAM andHABS (heavy alkyl benzene sulfonate)+strong base (NaOH)+HPAM, the stability ofemulsion of ternary combination system of petroleum sulfonate was lower than that of HABS.The viscosity of oil phase, the loss of light components of crude oil and the influence of somefactors such as adding n-butyl alcohol to surface active agents on the stability of crude oilemulsion were studied on the premise that the ratio of oil to water was1:1and the aqueousphase was binary system of AS (HABS+strong base). The results showed that the more thelight components of crude oil lose, the higher the viscosity of oil phase increase and the morestable the emulsion was; the higher the concentration of n-butyl alcohol was, the more stablethe emulsion was. By means of microscope, the relationship between the stability of emulsionof crude oil and the characterizing of the size distribution of disperse phase was studied. Theresults showed that the more disperse particles with small size in disperse phase were, themore stable the emulsion was.The variation of the oil-water ratio, concentration of ploymer surfactants, water salinityeffected on stability of water-in-crude oil emulsions in HaiBo TypeⅠ, Ⅲ ploymer surfactantssystem, which was investigated, the results showed that as the concentration of ploymersurfactants increased, the viscosity of TypeⅠ, Ⅲ ploymer surfactants increased, the morestable the emulsion was, the greater the proportion of the small particle in disperse phase was.When oil-aqueous volume ratio was1:1, ploymer surfactants with crude oil emulsion wasstable, stability of the emulsion decreased with oil-aqueous volume ratio reducing. Relationsbetween interfacial tension and stability of emulsion of TypeⅠ, Ⅲ ploymer surfactantssystem and ASP, SP system with crude oil, which was researched, found that low interfacialtension had no direct relevance with the stability of the emulsion. The salinity effected on theemulsion performance of ploymer surfactants system, which was investigated, found thatploymer surfactants had a better performance of salt-resistance and alkali-resistance, when the concentration of sodium chloride or sodium hydroxide was over12000mg/L, the stability ofemulsion of ploymer surfactants system got worse.The order of interfacial tension is ploymer surfactants system, binary system and ternarysystem. Dispersed panicle’s size of initial emulsification and interfacial tension showed thesame order. Low interfacial tension system is in favor of emulsifying dispersion. In the initialstate, the small particle size of the emulsion accounted for the large proportion. Ternarysystem of low interfacial tension’s drainage rate increased rapidly in process of subsidence.Dispersed particles coalesced and increased their diameter. The emulsion of higher ploymersurfactants system and binary system had good stability. The stability of emulsion andinterfacial tension had not corresponding relation.