  Yield-stress is a problematic and controversial non-Newtonian flow
phenomenon. In this article, we investigate the flow of yield-stress substances
through porous media within the framework of pore-scale network modeling. We
also investigate the validity of the Minimum Threshold Path (MTP) algorithms to
predict the pressure yield point of a network depicting random or regular
porous media. Percolation theory as a basis for predicting the yield point of a
network is briefly presented and assessed. In the course of this study, a
yield-stress flow simulation model alongside several numerical algorithms
related to yield-stress in porous media were developed, implemented and
assessed. The general conclusion is that modeling the flow of yield-stress
fluids in porous media is too difficult and problematic. More fundamental
modeling strategies are required to tackle this problem in the future.
