For Relative Permeability, the three flow solvers EJ, SimpleFFT, and LIR are available and can be chosen from the pull-down menu. For structures with low porosity, the SimpleFFT or LIR flow solver should be used for best performance, i.e., low runtimes. The solver settings are similar to those available in the FlowDict module, so please refer to the description in the FlowDict handbook for details. Note, that in FlowDict more options are available, that cannot be selected in the Relative Permeability options dialog (e.g. no restart options are available here).

Stop Relative to Fully Saturated Permeability

The option to Stop Relative to Fully Saturated Permeability is only available in SatuDict and relaxes the chosen stopping criterion for the computation of each partially saturated state.

First, the absolute permeability for the structure is computed, this yields the highest permeability value. For states with two fluids inside, the permeability of the selected flow phase will be smaller than the absolute permeability.

For the computation not the entered stopping criterion will be used, but it will be adapted to the absolute permeability. It is important to know how the stopping criteria work to understand how this option works.

E.g., if Error Bound is chosen as stopping criterion, the solver estimates the final solution and checks if the current solution is inside the error bound zone. An Error Bound of 0.01 means that the difference between current solution and predicted solution relative to the predicted solution must be smaller than 1% for the solver to stop. With Stop Relative to Fully Saturated Permeability activated the error bound will not be 1% of the predicted relative permeability in each run, but the error bound is a bit higher. For the exact value of the error bound, the absolute value of 1% of the absolute permeability is taken into account.

The effect becomes most visible for low saturations. Here, the permeability is near zero and the computation is much more expensive. With this option activated, the computation is stopped earlier, because the stopping criterion is more relaxed and thus earlier fulfilled.