高分散稳定性二硫化钼纳米片驱油体系及性能

Construction and Performance of MoS2 Nanoflooding System with High Dispersion Stability

高彦博 樊 辉 王 芳 周 娟 王筱晔 董宪鹏 逯力成

GAO Yanbo FAN Hui WANG Fang ZHOU Juan WANG Xiaoye DONG Xianpeng LU Licheng

在高盐低渗透油藏环境下，二硫化钼（MOS2）纳米片的分散稳定性差，往往需要和表面活性剂复配发挥协同作用以提高其性能，因此明确 MOS2与表面活性剂之间的相互作用对提高 MOS2的应用范围具有十分重要的意义。通过水热法，以硫代乙酰胺为硫源、三氧化钼为钼源合成了MOS2纳米片。研究了5种表面活性剂对MOS2纳米片在盐水中分散稳定性的影响，优选出阳离子表面活性剂十六烷基三甲基溴化铵（CTAB），考察了纳米驱油体系 CTAB-MOS2（质量比为 10∶1）的界面性能、乳化性能和提高采收率效果。结果表明，MOS2纳米片具有片层结构，在去离子水中的分散稳定性较好；随NaCl 质量浓度的增加，分散稳定性降低；CTAB可显著提高MOS2纳米片在 3000 mg/L NaCl 溶液中的分散稳定性。当MOS2质量分数为0.1%时，CTAB的加入可使MOS2的自稳定时间由不足 3 h 增长为 12 h；当 MOS2质量分数为 0.005%时，CTAB 的加入可使 MOS2的平均粒径由 122.7 nm 降为 98.1 nm，Zeta 电位绝对值由25.0 mV变为33.8 mV。0.05% CTAB-0.005% MOS2能在正庚烷/水界面处自发形成强度较高的界面膜和攀附膜，并可将正庚烷/水界面张力降低至0.175 mN/m，同时还具有较好的乳化效果。基于其优异的耐盐性以及良好的界面活性，CTAB-MOS2在低渗透环境下具有一定的提高采收率效果。在 60 ℃、3000 mg/L NaCl 的条件下，向低渗透（48.33×10-3 μm2）岩心注入 0.5 PV 0.05% CTAB-0.005% MOS2，可提高采收率 9.85 百分点。高分散稳定性CTAB-MOS2的构建有望为低渗透油田的高效开发提供解决方案，同时对于提高纳米材料的分散稳定性提供研究思路。

In the environment of high salt and low permeability reservoir，the dispersion stability of molybdenum disulfide（MoS2） nanosheet is poor，so it is often necessary to play a synergistic effect with surfactant to improve its performance. It is very important to clarify the interaction between MoS2 and surfactant to improve the application range of MoS2. By hydrothermal method，MoS2 nanosheets were synthesized with thioacetamide as sulfur source and molybdenum trioxide as molybdenum source. The effects of five surfactants on the dispersion stability of MoS2 nanosheets in saline was studied， and then the cationic surfactant hexadecyltrimethyl ammonium bromide （CTAB） was selected. The interfacial performance，emulsification properties and oil recovery effect of CTAB-MoS2（mass ratio of 10∶1）were investigated. The results showed that MoS2 nanosheet had layered structure，meanwhile the dispersion stability in deionized water was good. However，the dispersion stability decreased with increasing NaCl mass concentration. CTAB could significantly improve the dispersion stability of MoS2 nanosheets in 3000 mg/L NaCl solution. When the mass fraction of MoS2 was 0.1%，the addition of CTAB could increase the stabilization time of MoS2 from less than 3 h to 12 h. When the mass fraction of MoS2 was 0.005%，CTAB could reduce the average particle size of MoS2 from 122.7 nm to 98.1 nm，meanwhile the absolute Zeta potential value increased from 25.0 mV to 33.8 mV. 0.05% CTAB-0.005% MoS2 could spontaneously form a strong interface membrane and climbing membrane at the n-heptane/water interface. Furthermore，it could not only reduce the interface tension between n-heptane and water to 0.175 mN/m，but also have a good emulsifying effect. Based on its excellent salt tolerance and good interface activity，CTAB-MoS2 had certain enhanced oil recovery effect in low permeability environment. Under the condition of 60 ℃ and 3000 mg/L NaCl solution，when 0.5 PV 0.05% CTAB-0.005% MoS2 was injected into a low permeability（48.33 × 10-3 μm2）core，the oil recovery was enhanced by 9.85 percentage points. The construction of CTAB-MoS2 with high dispersion stability was expected to provide a solution for the efficient development of low permeability fields，and also provided research ideas for improving the dispersion stability of nanomaterials.

10.19346/j.cnki.1000-4092.2024.04.012