基质粒径变化对裂隙-基质系统中水流运动的影响规律研究

文章设计1组裂隙-基质模型,选用3种不同粒径的石英砂填充裂隙-基质系统的基质区域,研究不同粒径的石英砂对裂隙-基质模型中水流特征的影响。结果表明: Forchheimer方程的决策系数均高于达西定律的决策系数,与达西定律相比,Forchheimer方程能更好拟合裂隙-基质系统内流体的非线性流动; Kozeny-Carman模型模拟结果显示,3种基质粒径的裂隙-基质系统中基质渗透系数与特征粒径之间都呈线性关系; 裂隙-基质系统中水力开度越大,裂隙渗透性越弱,非达西渗流系数越大,非达西渗流现象越明显。

In this paper, a set of fracture-matrix models were designed, and three kinds of quartz sand with different particle sizes were selected to fill the matrix region of the fracture-matrix system, and the influence of quartz sand with different particle sizes on the water flow characteristics in the fracture-matrix model was studied. The results show that the decision coefficients of the Forchheimer equation are higher than those of Darcy's law, and the Forchheimer equation fits the nonlinear fluid flow in the fracture-matrix system better than Darcy's law. The simulation results of the Kozeny-Carman model show that there is a linear relationship between the matrix permeability coefficient and the characteristic particle size in the fracture-matrix system across all three matrix particle sizes. The larger the hydraulic opening in the fracture-matrix system, the weaker the fracture permeability, the greater the non-Darcy seepage coefficient, and the more obvious the non-Darcy seepage phenomenon.