乳状液稳定性影响因素及其分子动力学模拟研究进展

Research Progress on Influencing Factors of Emulsion Stability with Molecular Dynamics Simulation

油水乳状液的稳定性直接影响着油田地面生产系统中原油脱水及污水处理工艺技术的高效运行。针对原油极性组分沥青质、胶质,特别是实施三次采油化学驱中聚合物、表面活性剂等驱油剂返出对油水乳状液形成与稳定的影响,基于对宏观尺度研究这些因素影响所形成相关认识的综述,从可视化、乳状液体系密度分布、乳状液结构径向分布函数、油水界面形成能及分子扩散系数等表征出发,论述了分子动力学模拟在研究油水界面稳定机制方面的进展及软件平台。认为分子动力学模拟因具有微观结构表征的优势而已成为揭示相间界面作用的一种重要方法,同时,突破模型简化和单因素模拟的局限,综合内、外相组分特性,并兼顾温度、压力等外部因素,从微观尺度探究分子吸附、液滴聚并、液滴分离,是今后分子动力学模拟方法在油水乳化与破乳分离领域的研究应用和发展方向。图5参54。

The stability of emulsions presents a significant challenge in surface process particularly,both in terms of crude oil dehydration and produced water treatment.Considering the potential influence of asphaltene and resin in crude oil,especially the polymer and surfactant would be appeared in actual produced emulsions in chemical flooding process.This paper reviewed the application and research progress of molecular dynamics simulation in the field of oil-water interface stability mechanism.The available methods and relevant software for characterizing the visualization,density distribution,radial distribution function,oilwater interface formation energy,and molecular diffusion coefficient were discussed,respectively.In order to understand the interphase interaction of crude oil emulsions and address it,the molecular dynamics simulation could be used as an effective method according to the existed research.The review indicated that breaking through the limitations of model simplification and single factor simulation to understand the molecular adsorption,droplet coalescence,and droplet separation from micro-scale was a research application and development direction of molecular dynamics simulation in the fields of oil-water emulsification and demulsification.Furthermore,the component properties of internal phase and external phase,and the temperature and pressure conditions need to be considered.