Simulation of Polymer Flooding considering Size Model Increase and Economical Evaluation

Kemily Keiko Miyaji Sanches¹; Rosangela Barros Zanoni Lopes Moreno¹

¹ University of Campinas

doi:10.20906/CPS/CILAMCE2015-0709

Resumo

The water flooding is widely used because it is relatively simple and inexpensive. However, this method presents some disadvantages. Since water is usually low viscous than the oil, the water tends to arrive soon and in large quantities at the producer well, resulting in a low oil production due to the low swept efficiency. These conditions motivate the use of advanced recovery methods, and among them, polymer injection stands out. In this paper, the oil recovery by water injection alternated with polymer slug (WAP) is compared with continuous water flooding (WF). The results obtained for a laboratory scale model are compared with an equivalent upsized model, and finally their results are used in a simplified economic analysis. The study is conducted in a three-dimensional model using a commercial simulator, represented as a quarter of a five spot. WAP and WF are used as the base cases, and from them, other cases are analyzed. Variations on slug size, injection starting time of the polymer slug, relative permeability curves, polymer viscosity and mobile oil saturation were evaluated. All cases present the same period of exploitation, which allows the results comparison. Subsequently, the model was submitted to a size increase, and these results were used in an economic analysis based on the net present value (NPV). Considering a fixed exploitation period, and evaluating different polymer slug size, the WAP shows that larger slugs result in high amounts of produced oil. However, the oil amount per mass of polymer is low. The anticipation of polymer injection favors the anticipation of the oil production. More viscous polymer solutions reduce the mobility ratio, however, requires higher differential injection pressures. Low water relative permeability values at residual oil saturation lead to high oil production as a consequence of the small terminal mobility ratio. Small values of residual oil saturation result in higher oil recovery, regardless of the mobile oil fraction. The upsizing process does not present d

Palavras-chave: Polymer Flooding; Oil Recovery; Simulation; Upsizing; Economic Analysis