The effect of inaccessible pore volume and adsorption on polymer flooding for field scale injection in RZ field

Polymer flooding is an Enhanced Oil Recovery method to get better sweep efficiency when water flooding operations did not give good results for the oil displacement process in the reservoir. Based on the theory, the objective of polymer flooding is increasing injected water viscosity to make the mobility ratio decreases. Then, oil sweep efficiency becomes improved. As a result, the oil recovery factor becomes higher than water flooding. However, there is a case that polymer with higher viscosity does not always give the result oil recovery improvement. Two of the factors that affect the case are Inaccessible Pore Volume (IPV) and Adsorption. This paper aims to give a comparative analysis of the effect of IPV and Adsorption parameter on polymer displacement mechanism for field-scale polymer injection. The study of this paper was carried out by compositional reservoir simulation of field-scale polymer injection to specify the optimization of polymer IPV and Adsorption parameter. Two types of data inputted in compositional reservoir simulation are laboratory data and field data. Laboratory data represents the properties of polymer FP3630S, which include polymer concentration and rheology, polymer IPV and polymer adsorption. Polymer FP3630S has been used as an injected polymer in this simulation study. Field data represents the reservoir characteristics in RZ field, including geological reservoir model, reservoir PVT fluids, routine core and special core data, initial condition data, and production history data. Several scenarios have been applied for this investigation. The scenarios are set by the sensitivity of IPV and Adsorption parameter to analyze the polymer displacement mechanism based on sensitivity. The result of several scenarios gives various Recovery Factor (RF).