Optimization of Recovery under Injection of Biopolymer, Synthetic Polymer and Gels in a Heterogeneous Reservoir

For polymer injection, a comparison of xanthan polymer and synthetic polymer mechanisms was conducted. A commercial full-physics reservoir simulator is coupled with a robust optimization and uncertainty tool to run the model where a simplified gel kinetics is assumed to form a microgel with no redox catalyst. Water injection continues over all 6 layers for 450 days, followed by gel system injection for 150 days in the bottom 2 layers. Water injection is continued to 4 years. The top four layers have higher horizontal permeabilities and a high-permeability streak is at the bottom of the reservoir to reduce any helpful effects of gravity. Results demonstrate deep penetration of gel and blocking of the high permeability bottom layers. Sensitivity studies indicate the relative merits of biopolymer, xanthan polymer in terms of viscosity effects vs synthetic PAM in terms of resistance factor vs insitu gelation treatments and their crossflow dependence. Adsorption and retention of polymer and gel are permeability dependent.