1. A method practiced by a reservoir simulator for simulating a reservoir and generating a set of simulation results, said simulation results including a framework, the framework further including a plurality of grid cells, comprising: generating one or more static regions and one or more dynamic regions within the grid cells of the framework of the simulation results, the static and dynamic regions each having region values, one region value for each grid cell wherein region values identify grid cells in a region, wherein the region values of the static regions cannot be allowed to change dynamically, and wherein the region values of the dynamic regions can be allowed to change dynamically; receiving time varying data for at least one of the one or more dynamic regions; simulating the reservoir for an advanced time based at least in part on received time varying data; and updating the region values of the one or more dynamic regions depending on whether each of the one or more dynamic regions satisfies one or more conditions of a definition of a dynamic region.