Streamlines Simulation of Polymer Slugs Injection in Petroleum Reservoirs

Abstract

AbstractThe injection of polymer solutions is an effective method of Enhanced Oil Recovery. However, the continuous injection may be very expensive, and the injection of slugs is an alternative to improve the recovery factor. In this paper, streamlines simulation is used to model the 2D 2-phase oil displacement by polymer slugs, considering adsorption effects.Streamline simulation can be much faster than conventional finite difference models and its results may be used for slug polymer injection optimization in heterogeneous reservoirs. It decouples the 2D problem into multiple 1D problems along streamlines. The mass transport equations in the streamlines are solved analytically. The continuous polymer injection is a Riemann problem and its solution is self-similar, but in the case of slug injection, there are interactions between waves of different families. We analyze the results for several adsorption isotherms, like Henry and Langmuir.Analytical solutions are free from numerical diffusion, and allow the choice of greater time steps. The simulations were run in 2D incompressible models without gravity effects. Results obtained were compared with finite difference simulation. The analytical solutions along streamlines allowed the exact modeling of shock and rarefaction waves as well as the interaction between waves of same and different families. Sensitivity analysis was performed regarding the technique adopted for the cell concentration and saturation determination between time steps.