Patent ID: 7684967

Claim:
A method for conducting a reservoir simulation with the use of a reservoir model of a region of interest of a reservoir, the region of interest having been gridded into a plurality of cells, each cell having one or more unknown variable, each cell having a node, comprising the steps of: a) creating, using a computer, a graph of the cell nodes; b) imposing, using the computer, an initial decomposition of the graph into a pre-specified number of domains, such that each cell exists in at least one domain; c) numbering, using the computer, the cells and the domains, each cell having a key and each cell having a class, wherein a key of each cell is a set of domain numbers to which the cell belongs and the class of each cell being the number of elements in the cell's key; d) grouping, using the computer, the cells into connectors, each connector being a set of cells that share a same key, with each connector having a connector class, the connector class being the number of elements in a key of each connector; e) performing, using the computer, a connector reduction step to merge each connector that includes only one higher-order neighbor connector with such higher-order neighbor connector, wherein such higher-order neighbor has a higher class than the corresponding connector; f) resetting, using the computer, a class of all locally maximum class connectors to a maximum class held by any connector; g) forcing, using the computer, each of the locally maximum class connectors to contain only one cell; h) ordering, using the computer, the connectors in increasing order of class; i) constructing, using the computer, an interpolation operator and a restriction operator from the ordered connectors; j) using the interpolation operator and restriction operator to construct, using the computer, a coarse grid; k) conducting the reservoir simulation based on the coarse grid; and l) displaying the reservoir simulation.