Correlation structure effects on edge-accessible porosity and chemical distance near the percolation threshold

Toby Ewing, Iowa State University, and

Max Q. Hu, Lawrence Berkeley National Laboratory

Most studies in percolation theory assume a random infinite medium, while natural porous media are neither random nor infinite. A few studies have examined the impact of short-range correlation structure on the percolation threshold, but not its broader influence on fluid transport. Furthermore, there have been no investigations of longer-range correlation structures such as fBm. We investigate the impact of exponential and fBm random field connectivity structures on pore accessibility and tortuosity. In particular, we examine the porosity fraction which is accessible from the edge of the porous medium (e.g., a fracture face) but is not part of the infinite cluster. Near the percolation threshold, this portion of the porosity may have important contributions to long-term diffusion behavior in the presence of oscillating boundary conditions, such as intermittent wet/dry cycles inside Yucca Mountain.