硫化钼纳米片对油水界面特性的影响

Influence of Molybdenum Sulfide Nanosheets on Oil-water Interface Characteristics

冯 阳 侯吉瑞 兰夕堂 王栋森 代磊阳 高 尚

FENG Yang HOU Jirui LAN Xitang WANG Dongsen DAI Leiyang GAO Shang

新型纳米材料2-D纳米黑卡已被证实可有效提高低渗-致密油藏采收率，并展现出优异的油水界面特性。 但是其主要成分硫化钼纳米片对油水界面微观特性影响仍不明确。应用Lammps建立硫化钼纳米片模型，首先 就硫化钼纳米片尺寸进行优选。在常温常压（298 K，1 atm）条件下，针对优选出的硫化钼纳米片尺寸对油水界面 影响进行分子动力学模拟研究，分析硫化钼纳米片在油水界面的吸附形态、纳米片与油水界面交角对界面的影 响以及纳米片应力分析。模拟结果表明：30 ?×40 ?尺寸的硫化钼纳米片在油水界面作用时效果最佳；硫化钼纳 米片的存在，影响油水界面密度、厚度、界面交角、界面覆盖率；明确了硫化钼纳米片在油水界面作用机理：纳米片 上各点位应力影响其交角，交角影响界面覆盖率，但交角与界面覆盖率之间又存在相互竞争关系影响油水界面张 力的波动。本研究明确硫化钼纳米片对油水界面特性的影响，为2-D纳米黑卡驱油机理研究奠定理论基础。

It is proven that two-dimensional（2-D）black nanosheets can enhance effectively oil recovery in low permeability and tight reservoirs，showing excellent water/oil（W/O）interface characteristics. In order to clear the influence of molybdenum sulfide nanosheet，the main component of 2-D black nanosheet，on the microscopic characteristics of W/O interface，Lammps was used to establish the model of molybdenum sulfide nanosheet. Firstly，the size of molybdenum sulfide nanosheet was optimized. At room temperature and atmospheric pressure（i.e.，298 K and 1 atm），molecular dynamics simulation was conducted to investigate the effect of the selected size of molybdenum sulfide nanosheets on the oil-water interface. The adsorption morphology of molybdenum sulfide nanosheets at the oil-water interface，the effect of the intersection angle between the nanosheets and the oil-water interface on the interface，and the stress of the nanosheet were analyzed. The simulation results showed that the 30 ? ×40 ? molybdenum sulfide nanosheet had the best effect at the oil-water interface. The presence of molybdenum sulfide nanosheet affected the density， thickness，intersection angle and coverage of oil-water interface. The action mechanism of molybdenum sulfide nanosheet at the oil-water interface was clarified as follows，the stress at each point on the nanosheets affected their intersection angle，which affected the interface coverage rate. However，there was a competitive relationship between the intersection angle and the interface coverage rate，which affected the fluctuation of oil-water interface tension. This study clarified the influence of molybdenum sulfide nanosheet on oil-water interface characteristics，and laid a theoretical foundation for the study of oil displacement mechanism of 2-D black nanosheet.

10.19346/j.cnki.1000-4092.2023.03.016