Add a test to illustrate ACTNUM with CARFIN

[aritorto]

This PR adds a test with the purpose of illustrating improvements on refinement in Corner Point grids. Precisely, the old-requirements of

• all the cells must be active, and
• only Cartesian grids, are not necessary anymore.

Attached 2 screenshots of the grid with all the cells active, and 2 with 3 inactive cells (one of them inside the LGR, the other 2 cells outside the LGR).

The improvements on the refinement for Corner Point grids related to inactive/active cells are in OPM/opm-grid#734. Additionally, global refinement is in OPM/opm-grid#732. Finally, refine a mixed grid (with coarse and refined cells), in OPM/opm-grid#731.

[aritorto]

[aritorto]

jenkins build this please

[blattms]

I think we should add a comment about ACTUM (what cells are inactive) to the top comments in that file. E.g. "this test based on test ..., but we deactivated ..."

[blattms]

On the other hand, I am not sure whether it makes sense to have this test here. It has an injector well in the first cell and a producer in the last cell, but due to inactive cells between them there will be no flow. Hence it can be used to test the grid code but not really a full simulation.

It might make more sense to use the model in opm-grid only or to add another layer of cell to allow for flow.

[aritorto]

Thanks for your feedback @blattms! I knew that physically the test was not relevant. I'll draft this PR and work on a more meaningful test.

[aritorto]

Close it for being meaningless/non-relevant.