Bingham流体在双重多孔介质中径向渗流的分形模型

Fractal Analysis of Radial Seepage for Bingham Fluids in Dual-porosity Media

利用分形理论提出了Bingham流体在双孔隙率双重多孔介质中径向渗流的分形模型,得到了Bingham流体在双重多孔介质中启动压力梯度梯度及渗透率的分形解析表达式,它们可以表示成多孔介质的微结构参数和类树状分形分叉网络的结构参数、井筒半径及屈服应力的函数。研究结果表明Bingham流体在双孔隙率双重介质中的启动压力梯度随基质孔隙率及渗透率的增大而减小,随井筒半径的增加而增大。该理论模型与已有的理论解析结果吻合较好,证实了本模型的有效性。

Fractal analyzing expressions of Bingham fluid＇ s starting pressure gradient and permeability in radial composite dual-porosity medium are developed with the help of fractal models showing the radial flow behavior for Bingham fluids in and those expressions can be shown as the micro-structural parameters of porous media, structural parameters of the fractal-like tree networks, the well bore radius and the yield stress are presented. The results reveal that the starting pressure gradient for Bingham fluids in radial composite dual-porosity media decreases with the increase of porosity of matrix material and permeability, and increases with the increase of the radial distance. A good agreement obtained between the available theoretical analyzing results and our theoretical model verified the rationality of the present fraetal model.