Systems, computer-readable media, and methods for performing a reservoir simulation by obtaining reservoir data; translating the reservoir data into grid properties to create a grid; dividing the grid into domains; generating coarse grids corresponding to each domain; processing the domains, where processing a domain includes: calculating pressure for the domain using a coarse grid corresponding to the domain, calculating flux for the domain using a coarse grid corresponding to the domain, and calculating transport of fluids for the domain using a coarse grid corresponding to the domain; and generating a reservoir simulation corresponding to the grid based on processing each domain. The domains can be processed in parallel on different computer systems, different processors, or different cores.