Modeling of flow of bitumen in porous media
I want to model the shaft seal of repository in clay. The shaft seal consists of bentonite plugs and gravel column filled with bitumen. The goal of modeling is to investigate the behavior of bitumen under pressure, if it flows from shaft to exacavation damage zone or not. If we use EOS7 and set up viscosity and density of bitumen in properties of brine and for gravel elements set the brine mass fraction of 1 and for other elements 0. Does it mean that we model a system of rock+fluid of bitumen+fluid of water. Is it correct? Or since bitumen is non-newtonian fluid, we should use EOS3nn? I would appreciate your help!
Just briefly: What you propose (i.e., specifying a high "brine" viscosity) seems a valid first approximation to simulate bitumen. Note that the viscosity will be calculated as a function of brine/bitumen mass fraction (see Equations 8 and 9 in the manual).
Of course, bitumen is a non-Newtonian fluid, and using EOS3nn would be more appropriate, but given uncertainty in the bitumen rheology and other parameters, I would start with what you propose and then do a sensitivity analysis to examine the impact of your assumptions.