Flow Dynamics of Sulfate-Modified Water/Polymer Flooding in Micromodels with Modified Wettability

Abstract

This work describes the flow behavior of the oil recovery obtained by the injection of sulfate-modified/low-salinity water in micromodels with different wettabilities. It provides a detailed microscopic visualization of the displacement taking place during modified water flooding at a pore-scale level, while evaluating the effect of wettability on oil recovery. A comprehensive workflow for the evaluation is proposed that includes fluid–fluid and rock–fluid interactions. The methods studied comprise flooding experiments with micromodels. Artificial and real structure water-wet micromodels are used to understand flow behavior and oil recovery. Subsequently, water-wet, complex-wet, and oil-wet micromodels help understand wettability and rock–fluid interaction. The effect of the sulfate content present in the brine is a key variable in this work. The results of micromodel experiments conducted in this work indicate that sulfate-modified water flooding performs better in mixed-wet/oil-wet (artificial structure) than in water-wet systems. This slightly differs from observations of core flood experiments, where oil-wet conditions provided better process efficiency. As an overall result, sulfate-modified water flooding recovered more oil than SSW injection in oil-wet and complex-wet systems compared to water-wet systems.

Coupling Microfluidics Data with Core Flooding Experiments to Understand Sulfonated/Polymer Water Injection

“…Note that, we have observed the polymer sensitivity for mechanical degradation while flowing through chokes valves before entering into the core during our previous studies [ 21 , 22 ]. This investigation will further provide insight into polymer viscoelastic response while flowing through porous media.…”

“…This study is the extension of previous studies, which focused on the design of sulfate-modified/low-salt water-flooding for core plugs and micromodels [ 2 , 21 ]. This study also discusses the impact of sulfate on polymer viscoelastic behavior in porous media.…”

“…Among these active divalent ions (PDI), sulfate is the most effective ion [ 18 ]. We have previously proposed the mechanism of SO 4 −2 [ 19 , 20 , 21 , 22 , 23 ] for the wettability alteration in sandstone reservoirs. Similarly, from a fluid-fluid interaction point of view, sulfates can improve oil-brine interface resulting in oil phase snap-off suppression and increase the oil drop size [ 4 , 19 , 24 ].…”

Evaluation of 3D printed microfluidic networks to study fluid flow in rocks

“…The transparent sealing rubber enabled them to photograph the rock surface easily during the experiments. It should be noted that preparing microfluidic models from natural rock samples is challenging since the specimens should be thick enough to avoid chipping during the fabrication, but thin enough to precisely visualize the fluid flow over the entire grooved depth [23,24]. The main disadvantage of such setups is limitations in their reusability which contradicts the reason for employing such models.…”

Porous Bed Saturation Changes in Elution Process with Surfactant Solutions in Advanced Oil Recovery

“…These resources constitute a target for enhanced oil recovery (EOR) techniques. In recent decades, EOR methods were intensively developed and with their use significant amounts of oil can be recovered 3–7.…”