Abstract （报告摘要）

Water-based polymers are often used to improve oil recovery beyond a waterflood by improving the mobility ratio and    increasing sweep efficiency. However, polymer floods are not expected to affect residual (trapped) oil saturation. In this work, it is shown hat polymers, particularly those that are viscoelastic, can reduce residual oil saturation.

Bentheimer and Berea sandstone cores were saturated with either high (120cp) or low (< 10 cp) viscosity oil and then waterflooded to residual oil saturation. These floods were followed by injection of a water-based polymer, hydrolyzed polyacrylamide (HPAM), that was non-Newtonian and viscoelastic. Significant reduction in residual oil saturation was observed for all core floods when the polymer had significant elasticity, which contradicts conventional wisdom of the efficiacy of polymer flooding (improved sweep but not recovery of capillary trapped oil). Experiments in glass microfluidic channels and micromodels show unique flow behavior, including oscillation of oil droplets, at pores. Computational fluid dynamics modeling is used to explain the pheneomena by calculating the forces acting on a trapped oil droplet by a viscoelastic fluid. Finally, field scale simulations are performed for a real pilot study using a chemical flooding reservoir simulator. It is shown that viscoelastic polymer results in significantly larger recovery than even polymer floods that are not viscoelastic.  

 Bio （个人简介）

Matthew T. Balhoff is an associate professor in the Hildebrand Department of Petroleum and Geosystems Engineering at UT-Austin, where he has been since 2007. He received his BS (2000) and PhD (2005) in chemical engineering from LSU. He became an SPE    Distinguished member in 2017 and is a winner of the 2017 SPE    Southwestern North America Regional Reservoir Description and    Dynamics Award, 2014 SPE International Young Member Service Award,    and 2012 SPE International Teaching Fellow Award. Dr. Balhoff has    over 50 peer-reviewed publications in the areas of enhanced oil    recovery, carbon storage, unconventional resource production, and    fundmental processes of flow and transport through porous media.