The inner morphological structure of large pore paths is different from neither porous media nor pipes, thus the fluid flow mechanism in them is different from seepage flow and pipe flow. This paper aims to study the law governing fluid flow in large pore paths in unconsolidated sandstone reservoir. The similar number of the physical models of large pore path fluid flow was established based on dimensional analysis. Nine physical models were established with different mesh numbers of sand grains to investigate the relationship between differential pressure and flow rate in large pore paths under different extruding conditions of walls. The results show that the pressure gradient of flow resistance in the nine psychical models increased with the increasing of flow rate, and the higher the extruding degree of the wall, the larger the amplification of the pressure gradient. When the flow rate was increased to a certain value, the fluid flow changed from linear to nonlinear. Fluid flow in large pore paths, porous media and pipes was compared under the same cross-sectional area and same flow cross-sectional area, and the pressure gradient in large pore paths was lower than that of seepage flow but higher than that of pipe flow.

large pore path  /  physical simulation  /  large pore path fluid flow  /  seepage flow  /  pipe flow