特种油气藏2026，Vol.33Issue(1)：75-83,9.DOI:10.3969/j.issn.1006-6535.2026.01.009
CO2压力对羟基化和甲基化石英动态润湿影响的分子动力学研究
Molecular dynamics study of CO2 pressure effects on dynamic wettability of hydroxylated and methylated quartz
摘要
Abstract
To clarify the dynamic wettability changes during CO2 injection in unconventional reservoirs,molecular dynamics simulations were performed of water droplets wetting hydroxylated quartz and methylated quartz surfaces at various CO2 pressures.The study shows that hydroxylated quartz is initially strongly hydrophilic,while methylated quartz is initially weakly CO2-affine;as CO2 pressure increased,the water wettability of both decreased,with smal-ler changes for hydroxylated quartz and larger changes for methylated quartz.With higher CO2 pressure,CO2 and water molecules co-adsorbed on the methylated quartz surface,forming a discontinuous CO2 adsorption film that re-duced non-bonded interactions and led to lower hydrophilicity until at 44.96 MPa the water contact angle reaches to 180.00°.As CO2 pressure increases,the number of water molecules in the contact line region decreased and their motion space is compressed,reducing water molecular jump frequency and increasing jump distance.Compared with methylated quartz,hydroxylated quartz remains more hydrophilic with higher water molecule jump frequency and shorter jump distance.This study revealed the dynamic mechanisms of contact angle change for hydroxylated vs.methylated quartz under varying CO2 pressures,established relationships between contact angle,relative permeability and CO2 pressure and then a more accurate description of capillary pressure is proposed.These results provide new theoretical support for nanoscale fluid flow and a more reliable basis for reservoir evaluation,productivity prediction,and development strategy.关键词
分子动力学/CO2/羟基石英/甲基石英/动态润湿Key words
molecular dynamics/CO2/hydroxylated quartz/methylated quartz/dynamic wettability分类
能源科技引用本文复制引用
闫志明,王凤娇,刘义坤,初明旋,任梦瑶..CO2压力对羟基化和甲基化石英动态润湿影响的分子动力学研究[J].特种油气藏,2026,33(1):75-83,9.基金项目
国家自然科学基金"压裂-渗流-驱油方法多场耦合渗流机理研究"(52074087)、"振击压驱方法孔隙流体瞬时聚能微观力学机制及渗流机理研究"(52374035) （52074087）
