【作者】 陈晓星； 宋付权；

【Author】 CHEN Xiao-xing,SONG Fu-quan (College of Mathematics.Physics and Information Engineering.Zhejiang Normal University.Jinhua 321004, Zhejiang.

【机构】 浙江师范大学数理与信息工程学院；

【摘要】 在低渗透多孔介质中,流体流动时启动压力梯度的产生机理一直是近年来广大石油工程师探讨的问题。本文以平行板间液氩的Poiseuille流为例,用分子动力学模拟的方法,对壁面润湿性影响的启动压力梯度进行了研究。结果表明:强亲性(亲水性和亲油性)壁面附近,固液相互作用较强,液氩分子形成黏滞层,壁面附近液体的速度为零。边界黏滞层流体随外力增大逐渐被推动,绝对滑移长度随外力增大而减小,直至为零,之后滑移长度不再随外力增大而变化。本文成功解释低渗透多孔介质中液体流动的启动压力梯度的本质。最后从启动压力梯度产生的机理出发,得出结论:增大有效的采注压力梯度可以有效减小由启动压力梯度引起的不利影响。更多还原

【Abstract】 In recent years,when we discuss fluid flow in the low permeability porous media,the generation mechanism of threshold pressure gradient(TPG) is always a question to many petroleum engineers.In this paper,we take liquid Argon poiseuille flow between two parallel planes as the physical model and investigate the influence of wettability on TPG by Non-Equilibrium Molecular Dynamics(NEMD) simulation.The results show that,because of the strong solid-liquid interaction,velocities of liquid particles adjacent to hydrophilic boundary are zero,forming several stick layers.The stick layers are pushed forward gradually with the increase of external force.The absolute slip length decrease with the external force increasing,until reduce to zero and remain constant with the increase of driving force.This phenomenon can successively explain the essence of TPG in low permeability porous media. Based on the generation mechanism of TPG,we draw a conclusion that we can increase valid mining pressure gradient to reduce adverse effect caused by TPG.更多还原