Experimental study on porous media penetration based on laser etching technology

Permeability plays a pivotal role in water resources management, oil and gas exploration and production, as well as geological hazard assessment. Previous studies primarily explores the influencing factors of permeability through indirect methods, and lacks direct means to describe the relationship between porous media and permeability, and the relationship between permeability and the internal pore structure of porous media is still unclear. This study developed an experimental system featuring controllable pore space properties to investigate the relationship between permeability in porous media and factors including porosity, the horizontal and vertical distribution of pores, the regularity of particle arrangements, and the aspect ratio of elliptical pores. The experimental results demonstrate a positive correlation between permeability and porosity in porous media. Circular porous media generally adhere to the Kozeny-Carman equation, while variations in particle circularities and arrangements lead to pronounced permeability anisotropy. Due to the transverse arrangement of porous media leading to the fluid with a long flow path, permeability in horizontally arranged pores aligned with the flow direction is significantly higher than that in vertically arranged pores. Irregularly arranged porous media exhibit higher permeability compared to regularly arranged porous media, because 1) the irregular arrangement of the particles can lead to some large pores in the porous media that can provide large channels to facilitate the penetration of the fluid; 2) the irregular arrangement increases the flow path within the porous medium, leading to more fluid paths in the porous medium. Porous media with an aspect ratio of 1 for the long and short axes exhibits the highest permeability. The findings of this study provide essential insights into the evolution of penetration rates in porous media and their relationship with pore space properties.