Modeling of Gas-liquid Mixture Flow Considering the Processes of Gas Liberation and Dissolution

An approach to modeling multiphase flow of a gas-liquid compressible mixture taking into account the liberation and dissolution of gas is considered. Approach is based on an implicit pressure calculation using the finite element method and explicit phase transport. A computational scheme for modeling the processes of gas component transfer between oil and gas phases based on the known pressure dependence of the gas factor is described. In the considered approach the changes of phases volume appearing during the flow process are taken into account in the right-hand side of the equation used for pressure calculation. An iterative method for solving the obtained nonlinear boundary value problem for pressure calculation is described. This method based on the linearization of the pressure dependence of phases volume changes in the right-hand sides of the equation and boundary conditions. The verification of the proposed method is carried out on a test problem from the comparative project SPE-1. At each time step it takes an average of two nonlinearity iterations. The resulting plots of well data and gas phase distribution data are in good agreement with the results of the SPE-1 project participants.