Effects of residual resistance factor in the mobility control of the polymer flooding

Abstract

AbstractTo broaden the application of the polymer flooding in complex reservoirs, the residual resistance factor (RRF) is sought to make up for the limitations of high‐viscosity polymer flooding. First, the polymer solution rheology, adsorption and retention behaviors were mathematically characterized, and subsequently substituted into the equation of motion of the aqueous phase to build a mathematical model of the polymer flooding percolation. Second, based on the built numerical model, the formation process of seepage resistance and pressure propagation characteristics of polymers with a high RRF in the porous media were investigated. Lastly, the effects arising from viscosity and RRF on the flow control of the polymer flooding were explored by comparing the injection capacity, crude oil utilization and profile control capacity of different permeable formations at different development stages. As revealed by the results, the RRF was found to be more favorable than the “viscosity” parameter in improving the injection capacity at the polymer flooding stage. Moreover, it was found to slow down the water‐cut increase at the subsequent water flooding stage and reduce the difference between the oil recovery rate and injection pressure at different stages. Furthermore, the viscosity was primarily adopted to facilitate oil recovery of medium and high‐permeability formations by increasing the oil replacement efficiency, while the RRF was primarily dependent on the regulation of interlayer water absorption differences, thus mobilizing the remaining oil under the low‐permeability formations.