Effect of Polymer Injection on the Mobility Ratio and Oil Recovery

摘要

The fluids injection in oil reservoirs has the function to supplement the natural energy and in some cases is used to interact with the rock/oil system of reservoir, creating favorable conditions for oil recovery, for example lower interfacial tension, oil swelling, oil viscosity reduction and wettability modification. Polymer injection in heavy oil reservoirs is the subject of extensive studies since its implementation does not depend of major technological devices, requiring only mixing and filtration equipments in addition to those already used for common water injection. Moreover, polymers are not toxic and corrosive and can generate mobility ratios favorable in both borders of the injection seat. The adoption of this solution reduces the water/oil ratio of production, thus reducing the operational costs and consequently creating higher economic return. This work aims to evaluate the potential of polymer injection in heavy oil reservoirs. Therefore, using the reservoir simulation CMG′s IMEX, it was analyzed in heavy oil reservoirs the influence of the polymer injection on the mobility ratio, advanced water front during the breakthrough, the oil recovery factor and BSW. Tests with two models of reservoir were performed: homogeneous reservoir and heterogeneous stratified reservoir. Water injection was proposed as a comparison to the polymer injection method.