FLEXIBLE AND ADAPTIVE FORMULATIONS FOR COMPLEX RESERVOIR SIMULATIONS

摘要

A method for performing a simulation of a subsurface hydrocarbon reservoir is disclosed. Each cell in a reservoir model has an equation set representing a reservoir property. A stability limit is determined for each cell. Each cell is assigned to an explicit or implicit formulation. A solution to the system of equations is solved for using an initial guess and an explicit or implicit formulation. A stability limit is calculated for the converged cells. When the number of unconverged cells is greater than a predetermined amount, a reduced nonlinear system is constructed with a list of unconverged cells. The reduced nonlinear system is solved with the implicit formulation, and other cells are solved with the explicit formulation. Parts of the method are repeated until all equation sets satisfy a convergence criterion and a stability criterion, and the solved solution is output.