目的 考察稠油乳化降黏过程中无机盐在稠油乳状液油水界面上的增效协同作用。方法 根据分子动力学(MD)模拟技术，使用Materials Studio(MS)软件对无机盐以及十二烷基苯磺酸钠(SDBS)在稠油/水交界处的影响效应进行了模拟，应用径向分布函数(RDF)、界面生成能(EIF)、均方根位移(MSD)和界面层厚度等方法分析了无机盐(NaCl、MgCl2、CaCl2)对稠油乳状液油/水界面的影响，并在常温下通过降黏性能与界面张力实验验证无机盐对稠油乳状液的影响作用。结果 不同种类和浓度的阳离子与表面活性剂头基的相互作用导致其吸附层发生变化，改变了界面的聚集形态。阳离子的浓度和种类对油/水层具有不同程度的影响，改变了原来的水化结构，影响了油/水界面的稳定性，并用实验验证了无机盐对改善降黏效果和提高稳定性具有促进作用。在添加低浓度的无机盐离子后，使表面活性剂SDBS对稠油乳状液的作用得到改善和提高。结论 在无机盐质量分数为0.1%时，无机盐的加入降低了稠油乳状液的黏度，影响顺序由强到弱依次为Ca²⁺>Mg²⁺>Na⁺。但乳状液对Ca²⁺、Mg²⁺的“敏感性”比较大，再增加其浓度会对乳状液的降黏效果产生相反作用。

This paper aims to provide a more valuable reference method for safe and economic transportation of heavy oil, which can better improve the viscosity reduction effect and enhance its stability at normal temperature. Aiming at the problem of safe and economic transportation of heavy oil, which has been focused on by many scholars, the synergic effect of inorganic salts on the oil-water interface of heavy oil emulsion during the viscosity reduction process of heavy oil was specifically studied. According to the theory of molecular dynamics, various molecular models were obtained by MS. The oil model was built according to the four components in the heavy oil. After optimization and annealing treatment, the oil model and 996 water molecules were assembled together (8 SDBS molecules and inorganic salts were randomly dispersed within the water molecular box). A time step of 1 fs was selected, MD simulation of 500 ps under canonical ensemble (NVT) was performed, and then analysis was performed using the Forcite module. The RDF curve was used to analyze the microstructure information of particles in solution when different inorganic salt molecules (species and mass fraction) were added, the influence of NaCl on the stability of the oil-water interface was determined by EIF. The effects of various types of inorganic salts (NaCl, MgCl2 and CaCl2) on solution fluidity were analyzed based on MSD and diffusion coefficient (D), followed by an analysis of how inorganic salts affected the thickness of the oil/water interface using concentration distribution curves for simulated oil and water molecules along the Z-axis direction. In the verification part of the experiment, the oil and the emulsifier system aqueous solution were placed in a jacketed beaker (the emulsifier system was composed of an optimal mass concentration of 1.25% SDBS and inorganic salts). The heavy oil emulsion was preheated in a constant-temperature water bath at 25 ℃, then stirred with a multi-function agitator (HJ-5) at 400 r/min. After the heavy oil emulsion was obtained, the apparent viscosity was measured with a digital viscometer (DV-T2). The interfacial tension between the surfactant SDBS compound inorganic salt system and Liaohe‘s heavy oil was measured by a rotating drop interfacial tensiometer (JJ2000B). In the simulation, the interface thickness of the three systems (NaCl, MgCl2, and CaCl2) was 9.765, 10.793 and 11.307 ?, and the diffusion coefficients (D) of the three systems was (5.83, 5.13 and 4.81)×10?5 cm2/s. Experiments confirmed that inorganic salts could enhance the reduction of viscosity and stability of heavy oil emulsion under low concentration conditions. The viscosity increase of NaCl, MgCl2, and CaCl2 systems after 2 hours was 46.0, 14.1 and 6.6 mPa.s respectively. Among them, Ca2+ had the most significant effect, which could enhance various properties of surfactants. When the mass concentration of all three inorganic salts is 0.1%, the promoting effect of NaCl is poor at the same concentration, but increasing the concentration can further improve the synergistic effect. When 1.5% NaCl is added, the viscosity of heavy oil is 15 mPa.s, and the viscosity only increases by 11 mPa.s after 2 hours. However, increasing the concentration of CaCl2 and MgCl2 inhibits the emulsification effect of SDBS, and at the same time, the solution salts out, which has an adverse effect on the viscosity reduction of heavy oil.