Experimental study on Polymer Flooding in a Heterogeneous Porous Media-Part I: Effects of Copolymer and Silica Nanoparticles Composition

In the present study, acrylamide/2-acrylamido-2-methylpropane sulfonic acid (AM/AMPS) copolymers were synthesized for enhanced oil recovery (EOR). The effects of silica nanoparticles (SNPs) on the copolymer solution viscosity and oil recovery factor was investigated. Chemical structure of the copolymers and viscosity of the resultant aqueous solutions were determined using Fourier-transform Infrared (FTIR) spectrometer and an Ostwald viscometer, respectively. The functionality of the AMP55 copolymer in polymer injection test was studied using a glass micromodel. Oil recovery factor of 62.3% was obtained for injection of AMP55 copolymer. Additionally, the effect of SNPs on the solution viscosity and oil sweeping efficiency was studied. For this purpose, various amounts of SNPs (1, 2, and 3 wt.%) were added to the solutions with different AMP55 concentrations. Rheological results showed that incorporation of 2 wt.% of SNPs resulted in maximum viscosity of 42.8cs. Injection test results indicated that introduction of the 2 wt.% SNPs in the AMP55 solution enhanced the sweeping efficiency (71.7%) and recovery factor 15% and 400%, compared to the SNPs free copolymer solution and water flooding, respectively. The experiments led to proper selection of the synthesized copolymer structure and SNPs content in its solution, to attain the maximum viscosity and oil sweeping efficiency.