摘要
页岩油藏岩石的矿物组成复杂,不同矿物的表面性质(如润湿性)差异较大,对页岩油的流动具有重要影响,有必要研究不同矿物孔隙内页岩油的渗流机理。文中建立了有机质、石英和方解石所构成的页岩纳米孔隙模型,以正辛烷为例,采用分子动力学模拟方法研究了页岩油的微观流动特征,为构建准确的页岩油流动方程奠定理论基础。研究表明:1)受液固之间相互作用的影响,正辛烷在靠近固体壁面处形成吸附层;而在孔道中央处由于液固之间的作用力很小,正辛烷为游离相;2)压差驱动下正辛烷流动的速度剖面为抛物线形式,可以用考虑滑移的Poiseuille方程进行描述;3)不同矿物成分孔隙中正辛烷的流动速度由大到小依次为有机质、石英、方解石。
The rock mineral composition of shale reservoir is complex,and the surface properties(such as wettability)of different minerals vary greatly,which has an important influences on the flow of shale oil.It is necessary to study the seepage mechanism of shale oil in different mineral pores.Shale nanopore models composed of organic matter,quartz and calcite are established in this paper.Taking n-octane as an example,molecular dynamics simulation is used to study the microscopic flow characteristics of shale oil,which lays a theoretical foundation for constructing accurate shale oil flow equation.The study shows that the adsorption layer of the n-octane is formed in the vicinity of the solid surfaces caused by the liquid-solid interactions,while in the center of the pore,the n-octane is free phase due to the small interactions between the liquid and solid.The velocity profile of n-octane flow driven by pressure difference is of parabolic form and can be described by the slip-corrected Poiseuille equation.The flow rate of n-octane in pores with different mineral composition of organic matter,quartz,and calcite decreases from large to small.
作者
曹小朋
CAO Xiaopeng(Exploration and Development Research Institute,Shengli Oilfield Company,SINOPEC,Dongying 257015,China)
出处
《断块油气田》
CAS
CSCD
北大核心
2021年第5期609-613,共5页
Fault-Block Oil & Gas Field
基金
国家科技重大专项专题“济阳坳陷页岩油可流动性及产能评价研究”(2017ZX05049-004-004)
胜利2020年油气开发基础前瞻项目“济阳坳陷基质型页岩油流动机理研究”(P20058-1)。
关键词
页岩油
分子模拟
吸附
流动
矿物组成
滑移
shale oll
molecular simulation
adsorption
flow
mineral composition
slip
