Synthesis And Oil Displacing Capacity Of Gemini Surfactants With Ester Group

Oil is a very important fossil energy,improving oil recovery efficiency is the primary problem to be solved in oil field.In this paper,a series of sulfonated polymer surfactants(SPS-HA-n)were synthesized from AMPS,AM,St,BA and HA.The synthesis process of SPS-HA-n was optimized.Its structure was characterized by FITR and 1HNMR,and its molecular weight was measured by"one point method" in the range of 105 order.The results of surface tension showed that with the increase of HA content in long carbon chain,CMC decreased gradually,and the ? cmc of SPS-HA-11 could be as low as 33.019 mN/m.The results of particle size showed that the larger the amount of HA added,the easier the polymer surfactant surfactant to form micelles.The contact angle of SPS-HA-7 solution(101.03 g/L)on PTFE is 70.5°,which can change the hydrophobic PTFE surface into hydrophilic one.The emulsification results show that SPS-HA-n series polymer surfactants have good emulsification stability,and SPS-HA-9 has the best emulsification.The results of interfacial tension show that SPS-HA-7 can reduce the interfacial tension of oil and water to 0.0035 mN/m,reaching ultra-low interfacial tension.In this paper,the interfacial tension,emulsification and wettability of SAS-60/SPS-HA-n,Tween80/SPS-HA-n,SAS-60/Tween80/SPS-HA-n is discussed,The results show that when the proportion of sulfonate surfactant increases,the interfacial tension first increases and then decreases,and the emulsification performance first increases and then decreases after the compound of SAS-60/SPS-HA-n;With the increase of the proportion of sulfonate type polymer surfactants,the interfacial tension increased first and then decreased,and the emulsification performance also increased first and then decreased after the compound of Tween80/SPS-HA-n;With the increase of the proportion of sulfonate type polymer surfactants,the interfacial tension increases first and then decreases,and shows good emulsification performance after the compound of SAS-60/Tween/SPS-HA-n.In addition,the interfacial performance of the three surfactant composite system is better than that of the single surfactant and two surfactant composite system.The contact angle of sas-60/Tween80/sps-ha-n composite system is smaller than that of single surfactant,and its wettability is better.In this paper,the effect of different concentration of the same composite system(SAS-60/Tween80/SPS-HA-n)and different composite system(SAS-60/Tween80/SPS-HA-7)of the same concentration(3g/L)on the displacement efficiency is studied by the displacement experiment of artificial core to simulate the actual situation of oil production in the field.The results show that when the same system(SAS-60/Tween80/SPS-HA-7)has different concentrations of oil displacement,the water displacement efficiency has little difference in the water drive stage,but when the system is added with different concentrations of SAS-60/Tween80/SPS-HA-7 composite system,the oil displacement efficiency is significantly improved,and in the subsequent water drive stage,the oil displacement efficiency is not significantly different.When the concentration of SAS-60/Tween80/SPS-HA-7 composite system is 3g/L,the EOR of surfactant flooding stage is increased by 12.2%,and the final EOR is 51.5%;when the same concentration(3g/L)and different composite systems(SAS-60/Tween80/SPS-HA-n)drive oil,the EOR of SAS-60/Tween80/SPS-HA-7 composite system can be increased by 12.2%in surfactant flooding stage,and its performance is the best among the five composite systems.The final recovery of SAS-60/Tween80/SPS-HA-n system is 44.4%,48.9%,51.5%,50.6%and 50.1%respectively.In conclusion,the combination system of SPS-HA-n sulfonate polymer surfactant with SAS-60 and Tween80 has a very broad application prospect in oil displacement.