AN ITERATIVE COMPOSITIONAL MODEL FOR SUBSURFACE MULTIPHASE FLOW

The governing equations describing multiphase flow with multicomponent solute transport may be cast in a number of forms. While mathematical ly equivalent, the numerical models based on each formulation differ i n flexibility and efficiency. The set-iterative compositional formulat ion, a mathematical formulation that separates the solution of the pha se-balance equations from the species balance is described herein. A m athematical model based on this formulation describes the flow of two mobile phases. Each phase may transport multiple chemical components. Mass exchange between phases is expressed by a linear kinetic equation . The numerical model based on the set-iterative compositional formula tion is shown to model non-equilibrium phase partitioning, to provide a flexible framework that may be applied to organic mixtures with diff ering numbers of components and to yield a more efficient solution in comparison with models arising from standard compositional formulation s.