Novel insights on polymer properties: their effects on polymer flooding performance in thin heavy oil reservoirs

Heavy oil reserves in thin reservoirs are estimated to be 40% of remaining conventional oil resources. In these reservoirs, the primary production and waterflooding result in cumulative oil recovery as low as 10-20% due to adverse mobility ratio and water channeling. Moreover, thermal recovery methods are neither technically viable nor economically profitable due to severe steam channeling and considerable heat loss to surrounding formations. To solve the above problems, polymer flooding (PF) can be used as a cost-effective alternative, but the effects of polymer properties on economic performance of PF in thin reservoirs are still unclear. This study employs numerical simulations with net present value (NPV) as the objective function to analyze the effects of polymer properties. The results reveal that polymer concentration and permeability reduction benefit NPV, while polymer adsorption, inaccessible pore volume (IPV), shear-thinning and salinity have the adverse effects on NPV. A numerical sensitivity analysis is further conducted, and the results disclose that salinity, permeability reduction, and polymer concentration are the dominant properties influencing NPV of PF in thin heavy oil reservoirs, while shear thinning, IPV and polymer adsorption are statistically non-significant. This study provides insights on understanding each polymer property contribution to a cost-effective PF in thin heavy oil reservoirs.