A Modified Sequential Method for Solving the Full Composition Model in Numerical Reservoir Simulation

Abstract A modified sequential method (MSEQ) is proposed in this article to solve the full composition model in numerical reservoir simulation. During the iterative process, in order to solve the composition equations efficiently, the pressure field is treated as fixed temporarily, then the topological sorting algorithm is employed to update the saturation and mole friction field. Through the topological sorting for the grids from upstream to downstream, the full field coupled composition equations can be decoupled and solved with high efficiency as same as the explicit difference scheme. Numerical tests are performed and the high performance of the proposed MSEQ is illustrated. It can predict the simulation results with the same accuracy, and its computational speed is more than 2 times faster than the fully implicit method (FI) and the traditional sequential method (TSEQ).