Effects Of Anions On The Performance Of Cationic Surfactant

Some large oil reservoirs have reached the later stage of development and production.The application of surfactant in the oil and gas development has been received more and more attention,such as oil/gas drilling,mining,storage and transportation.In this paper,three series surfactant were synthesized.Some abilities were evaluated,including surface tension,foaming ability and stability,corrosion inhibition and emulsification ability.On this basis,foam micro structure were observed by microscopy which reveals the relationship between the mechanism of different foam decay and the foaming stability.It is summarized as follows:(1)A series of surfactants were synthesized with cetyltrimethyl ammonium chloride and sodium hydroxide,hydrofluoric acid,sodium bromide,sodium iodide as reactants.CTAF,CTAC,CTAB and CTAI effectively reduce the surface tension at 70?,the lowest surface tension of CTAI is 26.5mN/m,which is superior to that of the other surfactant.The optimal foaming concentration of different surfactant is 2.0g/L.CTAF has good foaming ability and foam stability at different temperature.The decay mechanism of different foams is gas diffusion.In 5% HCl solution,different surfactant has remarkably inhibiting efficiency.When concentration of surfactant solution is 5mg/L,the inhibiting efficiency of CTAI can reach 94.20% at 30?.The surfactant solution concentration is 5.0g/L,the emulsion is relatively stable by means of emulsification.(2)A series of surfactants were synthesized with cetyltrimethyl ammonium chloride and sodium hydroxide,acetic acid,propionic acid,butyric acid,lauric acid as reactants.CTAA?CTAP?CTAU?CTAL can effectively reduce the surface tension at room temperature.The lowest surface tension of the CTAA is 33.7m N/m,which is superior to that of the other surfactant.The optimal foaming concentration of different surfactant is 3.0g/L.Temperature,methanol,inorganic salts have a great influence on the foaming ability of the surfactant.In the presence of condensate,CTAP has a prominent foaming properties.When the condensate content is 0%,the initial foam volume reaches 410 m L.When the condensate content is 3%,the foam volume reaches 720 mL.In 5% HCl solution,four different surfactants have inhibiting efficiency,the concentration of surfactant solution is 30mg/L,the inhibiting efficiency of CTAA can reach 94.67% at 30?.(3)A series of surfactants were synthesized with cetyltrimethyl ammonium chloride and sodium hydroxide,oxalic acid,malonic acid,succinic acid,glutaric acid,adipic acid,sebacic acid as reactants.CTAO?CTAM?CTASU?CTAG?CTAA?CTASE effectively reduce the surface tension at 25?.The lowest surface tension of surfactant CTAO is reached 32.0mN/m,which is the best among the other surfactant.The optimal foaming concentration of different surfactant is 2.0g/L.In the presence of methanol,the foaming stability of foam is poor.When the concentration of anhydrous calcium chloride is 250g/L,the foam volume of CTASU is reached 415 m L and the half-life is 4.02 min,which is showed that CTASU has good salt resistance.the foams of CTAO and CTAM were all exhibited a regular spherical shape,while the foam of CTASU,CTAG,CTAA and CTASE changed from spherical to polygonal after 3min.In 5% HCl solution,six different surfactants have inhibiting efficiency.When the temperature is 30? and concentration is 30mg/L,the inhibiting efficiency of CTAO can reach 93.00%.