三元组分对弱碱三元复合驱模拟乳状液乳化稳定性的影响

Effect of ASP composition on the emulsion-stabilizing properties of simulative produced liquid by ASP flooding

考察弱碱三元组分对大庆油田石油磺酸盐三元复合驱模拟乳状液的乳化稳定动力学参数、界面黏弹性、扩散双电层Zeta电位等稳定参数的影响,研究三元组分对弱碱石油磺酸盐三元复合驱模拟乳状液乳化稳定性的影响规律。结果表明:表面活性剂的两亲性使其吸附于油水界面,质量分数的增加使其形成的油水界面膜稳定性增强,当表面活性剂质量分数高于0.1%时,形成的模拟原油采出液稳定较高,破乳较难;弱碱碳酸钠在三元复合体系起着双重作用,当碳酸钠质量分数小于0.8%时,碳酸钠主要与原油中的酸性物质生成表面活性物质,增加油水界面膜的强度,提高模拟乳状液乳化的稳定性,当碳酸钠质量分数大于0.8%时,碳酸钠的主要作用是中和表面活性剂分子在油水界面膜上的表面电荷,压缩油水界面扩散双电层,降低模拟乳状液的稳定性;聚合物主要是改善油水界面膜的黏弹性,其质量浓度的增加可使吸附在油水界面的有效分子数增多,油水界面的黏弹性增大,从而增强模拟乳状液的稳定性。

The influences of the ASP composition on the stability of weak base petroleum sulfonate simulation produced liquid by ASP flooding were studied,which were stable kinetic parameters,interface viscoelasticity and diffusion Zeta potential.And the influence mechanism of ASP composition on these parameters was investigated as well. The results show that the surfactant adsorbs at the oil-water interface due to its amphiphilic properties,and the stability of oil-water interfacial membrane increases with the increasing of surfactant mass fraction. When the concentration of surfactant is more than 0. 1%,the stability of the crude oil emulsion is increased,and then the demulsification becomes difficult. Sodium carbonate plays a dual role in the ternary compound system. When the mass fraction of alkali is less than 0. 8%,sodium carbonate reacts with the acidic substances in crude oil,and the surface active substances generates. The strength of oil-water interface membrane and the stability of the simulative produced liquid emulsion are increased because of the absorption of the surface active substances on the oil-water interface. When the mass fraction of alkali is more than 0. 8%,the main function of sodium carbonate is neutralizing the charge of the surfactant molecules in the membrane of oil-water interface. The diffused double layer of oil-water interface is compressed,and the stability of crude oil emulsion is decreased. The main role of polymer is increasing the viscoelasticity of oil-water interface. The effective numbers of molecules adsorbed on the oil-water interface increases with the increasing of polymer concentration. The viscoelasticity of oil-water interface is increased,and the stability of simulation produced liquid is enhanced.