Modified Soudium Petroleum Sulfonate Involving Enhanced Oil Recovery And Their Structures And Characteristics

In order to lower the cost of surfactant and improve its ability of resisting calcium and magnesium ions, a new kind of modified petroleum sulfonates PCS were synthesized from furfural extracted oil and vacuum distillate oil of Daqing refining oil company as raw materials respectively by Friedel-Crafts acylation with maleic anhydride and then sulfonation with Na₂SO₃. The reaction conditions and the structures of the two products were confirmed by IR and MS investigations referring to another modified sulfonate synthesized from dodecylbenzene. By comparing IR spectrum of the raw material oil with that of PCS, it was confirmed that PCS had both sulfonic acid group and carboxyl group. The average molecular weight, molecular weight distributing, average carbon number, mostly carbon number and alkyl carbon number of PCS were calculated from MS.The critical micelle concentrations (CMC) and the minimum surface tensions of the two PCS were measured by Wilhelmy plate method. The surface activity of PCS synthesized from furfural extracted oil was higher than that of PCS synthesized from vacuum distillate oil and also higher than that of the general petroleum sulfonate SPS synthesized from the same raw material.Interfacial tensions against Daqing crude oil of PCS were measured by spinning drop technique. The equilibrium interfacial tensions of PCS synthesized from furfural extracted oil were lower than those of PCS synthesized from vacuum distillate oil at various alkalinities. Moreover, the former could produce ultra-low interfacial tensions in a rather wide range of alkalinity whereas the latter could only produce ultra-low interfacial tensions at high alkalinities and surfactant concentrations. It was concluded that the ability in lowering the interfacial tension of PCS synthesized from furfural extracted oil was better than that of PCS synthesized from vacuum distillate oil.The interfacial tension between the PCS synthesized with two different raw material oil and Daqing crude oil can be retained below calcium and magnesium concetration of 600mg/L,Both of the two modified petroleum sulfonates could produce ultra-low interfacial tension at calcium and magnesium ions concentration lower than 600 mg/L, whereas the general petroleum sulfonates could only produce ultra-low value below 300 mg/L, which showed thatthe ability of resisting calcium and magnesium ions of PCS was better than that of SPS. It was found that the modified petroleum sulfonates synthesized in this thesis were a kind of low costing and salt resisting surfactants having good ability in lowering interfacial tension for enhanced oil recovery.