system and method for flexible and efficient simulation of varying fracture density in a reservoir simulator

摘要

system and method for flexible and efficient simulation of varying fracture density in a reservoir simulator system and method for a reservoir represented by a model having a plurality of matrix nodes, a plurality of fracture nodes, a fracture zone and a fracture free zone are described. One embodiment includes computer-implemented steps of, for each of a plurality of matrix nodes in interconnected zones, characterizing matrix nodes as double matrix nodes or non-double matrix nodes. Double matrix nodes can be treated as a block and dropped, after which the coefficient matrix and rhs vector for the model are updated. Fill patterns between and belonging to fracture nodes and non-double matrix nodes resulting from the deletion are determined. For non-double matrix nodes, the nodes are merged into a fracture grid, after which the coefficient matrix and rhs vector for the model are updated. The resulting linear system is linearly resolved, and reverse solution is performed for any eliminated double matrix node.