摘要
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,展现出优异的油水界面特性。但是2-D纳米黑卡与油水界面相互作用的微观机理仍不明确。应用Lammps建立2-D纳米黑卡油水界面模型,针对常温常压(298 K,1 atm)条件下2-D纳米黑卡在油水界面的特性进行分子动力学模拟,分析2-D纳米黑卡个数对不同分子在油水界面的密度分布、油水界面厚度、油水界面覆盖率、分子间相互作用能和界面张力变化率等5个关键参数的影响规律。模拟结果表明:当2-D纳米黑卡界面覆盖率近似为1时,界面处油水及纳米片分子密度分布基本达到稳定,2-D纳米黑卡界面密度峰值几乎不再增长,密度峰变宽;油水界面厚度为24.4Å,油水界面相互作用能为-4164 kcal/mol,界面张力比率为0.767,且这3个量达到相对稳定状态。本研究可对2-D纳米黑卡室内实验和矿场应用浓度优选提供理论依据和指导,为纳米片驱油机理的研究奠定理论基础。
A flaky two-dimensional(2-D)black nanosheet has been proven to be effective in enhancing oil recovery in low permeability and tight reservoirs,showing excellent water/oil(W/O)interface characteristics.However,the microscopic mechanism of 2-D black nanosheet interaction with W/O interface is still unclear.A molecular dynamics study was presented to reveal the characteristics of 2-D black nanosheet at W/O interface which was performed using the Lammps package at room temperature and atmospheric pressure(i.e.,298 K and 1 atm).The influence of the number of 2-D black nanosheet on the density distribution of different molecules at the W/O interface,the thickness of the W/O interface,the rate of interface coverage(RIC),the intermolecular interaction energy,and the rate of interfacial tension,was analyzed.The results showed that when the 2-D black nanosheets number was four,that is,RIC was approximately one,the W/O interface density distribution was stable in the MoS2 nanosheets W/O interface model.The peak density of the 2-D black nanosheets’interface almost did not increase,but the peak density became wider.Moreover,the interface thickness was 24.4Å;the interaction energy was−4164 kcal/mol,and the interfacial tension ratio was 0.767 at the W/O interface,which was relatively stable.The study of 2-D black nanosheet can provide theoretical basis and guidance for their laboratory experiment and concentration optimization of field application,and lay a theoretical foundation for the study of nanosheet oil displacement mechanism.
作者
冯阳
侯吉瑞
杨钰龙
王栋森
王立坤
程婷婷
刘彦伯
FENG Yang;HOU Jirui;YANG Yulong;WANG Dongsen;WANG Likun;CHENG Tingting;LIU Yanbo(Unconventional Oil and Gas Institute,China University of Petroleum(Beijing),Beijing 102249,P R of China;Key Laboratory of Petroleum Engineering(Ministry of Education),China University of Petroleum(Beijing),Beijing 102249,P R of China;China National Offshore Oil Corporation Safety&Technology Services Company Limited,China National Offshore Oil Corporation,Tianjin 300459,P R of China;Key Laboratory of Complex Oil&Gas Fields Exploration and Development,Chongqing University of Science&Technology,Chongqing 401331,P R of China)
出处
《油田化学》
CAS
CSCD
北大核心
2022年第2期311-317,共7页
Oilfield Chemistry
基金
国家十三五重大专项“低渗-致密油藏高效提高采收率”(项目编号2017ZX05009)。
关键词
2-D纳米黑卡
微观驱油机理
界面形态
分子动力学
LAMMPS
2-D black nanosheet
micro oil displacement mechanism
interfacial interaction
molecular dynamics simulation
LAMMPS
