Summary of results ====================== This test case provides a classic problem in numerical modeling of underground storage: the injection of gas into a saturated environment in :math:`\mathrm{2D}`. We do not have reference solutions to compare ourselves with, but the values and the format of the results are typical for this type of problem. So we are making it a non-regression test case. This test is treated with the 2 numerical diagrams available for modeling two-phase flows: * the decentralized edge finite volumes diagram. * Classic finite elements. The results obtained are the same. In terms of performance and reliability, we strongly favor Decentralized Finite Volume Decentralized Edge schemes (* _ HH2SUDA).