Numerical Simulation of Oil Reservoir Polymer Flooding by the Model of Fixed Stream Tube

The work is devoted to development of high-speed mathematical model for accurately simulating the complex process of polymer flooding of oil reservoir. The proposed technique based on the use of fixed stream tube model. The technique consists of two steps. First, the stream lines and stream tubes from the injection well to surrounding producer wells defined from the solution of the thickness averaged two-dimensional problem of steady state flow. Then to describe the polymer flooding in each stream tube the problems of two-phase (water, oil) three-component (water, oil, polymer) flow are solved on a detail grid with a lateral mesh size to 1 meter, and with the vertical step of about 20 centimeters. Decomposition of the source three-dimensional problem to a series of two-dimensional problems allows to use high-resolution grids to describe the «thin» features of the viscous rim moving process. The viscosity of the aqueous solution of polymer is given as a function of concentration and shear rate. Model allows to make rapid simulations of different scenarios of polymer flooding, assessing the efficiency, and to determine the optimal parameters of development. The article demonstrated examples of numerical simulation of polymer flooding of a layered formation at different polymer injection modes.