基于逾渗网络模型的弥散系数与渗透率关系研究

发布时间：2018-03-09 19:06

本文选题：网格模拟　切入点：弥散系数　出处：《水动力学研究与进展(A辑)》2017年04期 　论文类型：期刊论文

【摘要】：该文基于逾渗理论和网络模型,建立体中心网格(BCC)的三维孔隙网络模型,在周期性边界条件下模拟不同孔隙半径变异系数及不同孔隙连通性下的弥散过程。假设微粒在单管中服从Taylor-Aris弥散,其通过单管的时间可由累积分布函数随机获得;流体在管束节点处发生完全混合,随后按照节点连接管束的体积流量比对应的概率随机进入一根管束,以此实现微粒的不断运移。利用粒子追踪法确定固定时间下的微粒位置,并根据矩量法计算弥散系数。模拟结果表明弥散系数随孔隙连通性的降低而增大,随水力半径的增加而增加,且均遵循相应的乘幂关系。结合渗透率模型,探索了弥散系数与渗透率间的关系,并与实验结果进行对比,验证了模型的正确性。
[Abstract]:Based on percolation theory and network model, a three-dimensional pore network model based on three-dimensional central mesh (BCC) is established in this paper. The dispersion process of different pore radius variation coefficient and different pore connectivity is simulated under the periodic boundary condition. Assuming that the particles are dispersed from Taylor-Aris in a single tube, the time of passing through a single tube can be obtained by the cumulative distribution function randomly. The fluid is completely mixed at the node of the tube bundle, and then, according to the corresponding probability of the volume flow ratio of the node connecting the tube bundle, the fluid enters a tube bundle at random to realize the continuous migration of the particles. The particle tracing method is used to determine the position of the particles at a fixed time. The simulation results show that the dispersion coefficient increases with the decrease of pore connectivity and increases with the increase of hydraulic radius, and follows the corresponding power relation. The relationship between diffusion coefficient and permeability is explored and compared with experimental results to verify the correctness of the model.
【作者单位】：西南石油大学石油与天然气工程学院;
【基金】：石油化工联合基金(A类)项目(U1562217) 国家重点基础研究发展计划(2015CB250902)~~
【分类号】：TV139.1

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