Study On Synthesis Of Alcohol Ether Carboxylate (AEC) And Synergistic Effect Of AEC With Petroleum Sulfonate

Chloroacetic acid and alkyl ethers with different carbon chain length and number of ethylene oxide(or oxygen propylene)were used as raw materials,with the existence of powdery NaOH,15 kinds of alcohol ether carboxylate(AEC)surfactants were synthesized in the way of carboxymethylated method.Method of two phase titration was used to determine the yield of target products.Yield of AEC above 70% could be achieved when alkyl alcohol ether,chloroacetic acid,NaOH and ethanol were added at the molar ratio of 1:2:2:4,with 1h for basification and 4h for chemical reaction at the temperature of 50?,.Relations between the molecular structure of AEC,simulated water salinity and oil/water interfacial tension(IFT)were investigated.It was found that for AEC with same carbon chain length,the more ethylene oxide,the higher the equilibrium IFT values,and for AEC with both ethylene oxide(EO)and oxygen propylene(PO),the more PO,the lower the equilibrium IFT values wew.And experimental results also showed that simulated water salinity had little effect on IFT of AEC.Besides,phase behaviors showed that the optimal NaCl salt content of 12AC-0-9 was below that of 16AC-0-9 and 18AC-0-9,and the optimal NaCl salt content of 12AC-0-9 was between 12%~14%NaCl.In addition,the synergistic effects of solubleness and IFT of the mixture of AEC and KPS were investigated.The results indicated that AEC with 9 and 12 EO could significantly improve KPS's water solubility;and synergistic effect on IFT came out between KPS and 16AC-0-9/18AC-0-9,thus lower balance IFT value could be reached than any single component.For compounded systems of KPS and 16AC-0-9/18AC-0-9,IFT sharply fell to ultra-low values and no rapid rising in simulated water containing only NaCl,and when ions content doubled in the simulated water,IFT were the lowest.Phase behavior experiments showed that the optimal NaCl salt content of KPS is 1.0% NaCl,and that of KPS and 16 AC-0-9 mixture at mass ratio of 2.5:1 is 2.8%,KPS and 18 AC-0-9 mixture at mass ratio of 2.5:1 is 3.2%.Oil displacement experiment results showed that flooding system of 0.3wt%KPS and 0.15wt%HPAM improved oil recovery by 14.3%,and 0.3wt%(KPS: 18AC-0-9 = 2.5:1)with 0.15wt% HPAM flooding system could enhance the recovery by 18.5%.