A NUMERICAL-METHOD FOR SIMULATING NON-NEWTONIAN FLUID-FLOW AND DISPLACEMENT IN POROUS-MEDIA

Flow and displacement of non-Newtonian fluids in porous media occurs i n many subsurface systems, related to underground natural resource rec overy and storage projects, as well as environmental remediation schem es. A thorough understanding of non-Newtonian fluid flow through porou s media is of fundamental importance in these engineering applications . Considerable progress has been made in our understanding of single-p hase porous flow behavior of non-Newtonian fluids through many quantit ative and experimental studies over the past few decades. However, ver y little research can be found in the literature regarding multi-phase non-Newtonian fluid flow or numerical modeling approaches for such an alyses. For non-Newtonian fluid flow through porous media, the governi ng equations become nonlinear, even under single-phase Bow conditions, because effective viscosity for the non-Newtonian fluid is a highly n onlinear function of the shear rate, or the pore velocity. The solutio n for such problems can in general only be obtained by numerical metho ds. We have developed a three-dimensional, fully implicit, integral fi nite difference simulator for single-and multi-phase flow of non-Newto nian fluids in porous/fractured media. The methodology, architecture a nd numerical scheme of the model are based on a general multi-phase, m ulti-component fluid and heat flow simulator-TOUGH2. Several rheologic al models for power-law and Bingham non-Newtonian fluids have been inc orporated into the model. In addition, the model predictions on single -and multi-phase flow of the power-law and Bingham fluids have been ve rified against the analytical solutions available for these problems, and in all the cases the numerical simulations are in good agreement w ith the analytical solutions. In this presentation, we will discuss th e numerical scheme used in the treatment of non-Newtonian properties, and several benchmark problems for model verification. In an effort to demonstrate the three-dimensional modeling capability of the model, a three-dimensional, two-phase flow example is also presented to examin e the model results using laboratory and simulation results existing f or the three-dimensional problem with Newtonian fluid flow. (C) 1998 E lsevier Science Limited. All rights reserved.