Three dimensional numerical modeling of multiphase flow and transport.

The coupled multiphase flow and transport problem is solved by the finite element method, using linear three-dimensional tetraeder elements. The three-phase flow problem is solved simultaneously for the fluid pressures. The strong nonlinearities are treated with a Newton-Raphson iteration scheme with relaxation. Due to the kinetic of interphase mass transfer and reactions, the equations for water, gas, and solid phase concentrations are strongly coupled. Therefore, both transport equations for water and gas are solved simultaneously, while the equation for the solid phase is solved directly. The numerical model was tested with analytical, quasi-analytical and other numerical models. After the verification first applications were performed.