Simulation Study of Imroving Heavy Oil Recovery by Polymer Flooding in a Heterogeneous Layered Reservoir

Due to the capillary pressure, unfavourable mobility ratio, reservoir heterogeneity, and lack of reservoir energy, typically more than 50% of original oil in place is left in the reservoir after primary depletion and secondary recovery mode. Water injection to maintain reservoir pressure after primary depletion and to displace oil in the secondary mode, often causes flow channelling and leaves substantial bypassed oil in heterogeneous layered reservoirs. Polymer flood is a commercially proven technology to enhance oil recovery from mature reservoirs. Reservoir simulation of polymer flood plays a significant role in determining the economic potential of polymer flood in a specific field. However, complex physics of polymer rheology in porous media is hard to capture in reservoir condition via reservoir simulation. Therefore, reservoir simulators with special features are essential to represent coupled chemical and physical processes present in chemical enhanced oil recovery methods such as polymer flood. The simulators need to be first validated against well-controlled lab and pilot scale experiments to have reliable predictions of the full field implementations. In this paper, the potential of polymer flood is studied and several sensitivity cases are performed to evaluate the effect of various physical property parameters on oil recovery for synthetic heterogeneous layered reservoir. In addition, 1-D core flood tests are history matched using chemical compositional simulator (UTCHEM) to validate the pilot scale simulation results more accurately. Simulation results show that injecting polymer solution can improve sweep efficiency of low permeable zone of the model compared to the conventional water flood. Moreover, optimum polymer concentration, solution salinity, well pattern size, and injection time are the main factors influencing the polymer flood performance for the pilot model.

کلیدواژه ها:

IOR ، Polymer Flooding ، Reservoir Simulation ، UTCHEM