Speaker
Description
Polymer flooding for enhanced oil recovery (EOR) has traditionally focused on viscosity enhancement to improve macroscopic sweep efficiency and is often assumed to have a negligible impact on microscopic oil displacement. The viscoelastic properties of polymer solutions flowing through porous media remain insufficiently explored, despite their potential to significantly enhance oil displacement efficiency.
In this study, the pore-scale flow behavior of aqueous hydrolyzed polyacrylamide (HPAM) solutions are investigated with particular emphasis on the role of elasticity in microscopic oil displacement. To isolate elastic effects, a series of HPAM solutions were formulated to have identical shear viscosities but systematically varying elastic properties. Rheological characterization confirmed that all fluids exhibited matched viscosities while showing substantial differences in storage moduli, thereby enabling a clear decoupling of viscous and elastic contributions.
These model fluids were employed in pore-scale displacement experiments using micromodels featuring pore throats, dead-end structures, and porous networks representative of reservoir rock. Experiments were conducted under reservoir-relevant conditions to assess the influence of elasticity on flow behavior and oil mobilization. High-resolution microscopic imaging revealed three dominant elasticity-driven displacement mechanisms: (i) a pull-out or stripping effect, (ii) elastic turbulence, and (iii) elastic normal stresses. By controlling viscous and capillary forces, this study isolates the direct contribution of elasticity to oil mobilization. The results demonstrate that increased elastic forces significantly enhance the mobilization of trapped oil at the pore scale, leading to improved microscopic displacement efficiency.
Complementary computational fluid dynamics (CFD) simulations were performed across a range of fluid elastic properties and porous geometries to further elucidate the underlying flow mechanisms and validate experimental observations.
Overall, this work presents a rigorous and systematic methodology for isolating and quantifying polymer elasticity effects independent of viscosity in EOR applications. By combining viscosity-matched viscoelastic fluids, pore-scale experiments, and CFD simulations, the study provides direct evidence of how elasticity enhances microscopic oil displacement. The findings offer practical guidelines for the rational design of viscoelastic polymer flooding strategies and establish a foundation for optimizing field-scale injection schemes that leverage both viscous and elastic forces to maximize oil recovery in heterogeneous reservoirs.
| Country | India |
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