以砂岩中含量最高的二氧化硅为主要研究对象，对二氧化硅壁面分别进行了羟基（—OH）化和甲基（—CH₃）化处理代表亲水和疏水壁面，运用LAMMPS软件进行分子动力学对超临界CO₂萃取原油组分的过程进行模拟研究。结果表明：温度为333.15 K、压力为20 MPa时，超临界CO₂萃取出羟基化二氧化硅壁面的饱和烃分子比甲基化二氧化硅壁面的多5.07%；原油组分与两种壁面的相互作用能均为吸引关系，饱和烃分子的相互作用能下降幅度最大分别为 77.52% （羟基化二氧化硅壁面）和46.04%（甲基化二氧化硅壁面）且甲基化二氧化硅对饱和烃的相互作用能大于羟基化二氧化硅壁面；CO₂容易萃取出分子链较短的饱和烃分子，原油组分在两种壁面条件下的扩散系数大小为饱和烃>胶质>芳香烃>沥青质。

The silica with the highest content in sandstone was taken as the main research object. The SiO₂ surfaces underwent hydroxyl (—OH) and methyl (—CH₃) treatments to represent the hydrophilic and hydrophobic walls, respectively. LAMMPS software was utilized to implement molecular dynamics simulations and replicate the process of supercritical CO₂ extraction of crude oil components. The results indicate that the temperature is 333.15 K and the pressure is 20 MPa. The hydroxylated silica surface extracted 5.07% more saturated hydrocarbon molecules using supercritical CO₂ compared to the methylated silica surface. The interaction energy between the oil components and the two wall surfaces is mutually attractive. The interaction energy of saturated hydrocarbon molecules decreases by 77.52% for hydroxylated silica surface and 46.04% for methylated silica surface, respectively. Additionally, the interaction energy of methylated silica on saturated hydrocarbon is greater than that of the hydroxylated silica surface. It is important to note that carbon dioxide easily extracts saturated hydrocarbons with short molecular chains. The diffusion coefficients of crude oil components under two surface conditions are saturated hydrocarbons > resins > aromatic hydrocarbons > asphaltenes.