The dynamics of capillary-driven two-phase flow: The role of nanofluid structural forces

Nikolov, Alex; Zhang, Hua

doi:10.1016/j.jcis.2014.10.057

Cited by 16 publications

(7 citation statements)

References 73 publications

(111 reference statements)

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“…In contrast, a polymeric nanofluid containing polyethylene glycol 8000 (Fisher Scientific, USA) dispersed in brine is relatively stable with respect to electrolytes or temperature. In order to enhance the effect of the structural disjoining pressure on the oil recovery process, the nanofluid composition was selected based on a multistep process. , The size and polydispersity of the polymeric nanofluid in brine were characterized by the dynamic light scattering method (Malvern Instruments, UK). The average diameter was found to be 9.5 ± 0.5 nm, with a polydispersity of around 8–10% at 25 °C.…”

Section: Methodsmentioning

confidence: 99%

Enhanced Oil Recovery Driven by Nanofilm Structural Disjoining Pressure: Flooding Experiments and Microvisualization

2016

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Nanofluids composed of liquid suspensions of nanoparticles may soon permit accelerated recovery of hydrocarbons from oil and gas reservoirs. Here, we present a series of flooding experiments at different capillary numbers to quantify the performance of a polymeric nanofluid compared to brine using the sintered glass-beads. A high resolution X-ray microtomography (micro-CT) was used to visualize oil and brine distribution in a sintered bead pack before and after nanofluid flooding. The results of flooding experiments showed that an additional oil recovery of approximately 15% is possible with nanofluids compared to brine at low capillary numbers and is as effective as high capillary number brine flooding. Nanofluid induced additional oil recovery decreases as we increase the capillary number, and the total oil recovered shows a marginal decrease. At first glance, these results are opposite of what one expects in the conventional EOR, where oil recovery is known to increase progressively with increasing capillary number. These results cannot be explained based on mobilization theories due to the reduced capillarity. Our results however are consistent with the mechanism of wettability alteration caused by structural disjoining pressure leading to the formation of the wetting nanofluid film between oil and substrate. Unlike brine displacement, X-ray micro-CT images show that mobilization of oil from the porous medium by a nanofluid is fairly uniform even at low capillary numbers and large-scale clusters of oil are absent. Our findings in this paper are expected to promote the understanding of EOR by nanofluids.

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Section: Methodsmentioning

confidence: 99%

Enhanced Oil Recovery Driven by Nanofilm Structural Disjoining Pressure: Flooding Experiments and Microvisualization

2016

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“…The LWR equation has numerous important applications in areas such as inkjet printing, , food processing, and petroleum engineering . It can describe the flow dynamics of a liquid penetrating into capillaries and can be used to determine the physical–chemical properties of porous media and liquids, such as the contact angle, the pore size, and liquid surface tension …”

Section: Introductionmentioning

confidence: 99%

Capillary Rise: Validity of the Dynamic Contact Angle Models

Nikolov

2017

Langmuir

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The classical Lucas-Washburn-Rideal (LWR) equation, using the equilibrium contact angle, predicts a faster capillary rise process than experiments in many cases. The major contributor to the faster prediction is believed to be the velocity dependent dynamic contact angle. In this work, we investigated the dynamic contact angle models for their ability to correct the dynamic contact angle effect in the capillary rise process. We conducted capillary rise experiments of various wetting liquids in borosilicate glass capillaries and compared the model predictions with our experimental data. The results show that the LWR equations modified by the molecular kinetic theory and hydrodynamic model provide good predictions on the capillary rise of all the testing liquids with fitting parameters, while the one modified by Joos' empirical equation works for specific liquids, such as silicone oils. The LWR equation modified by molecular self-layering model predicts well the capillary rise of carbon tetrachloride, octamethylcyclotetrasiloxane, and n-alkanes with the molecular diameter or measured solvation force data. The molecular self-layering model modified LWR equation also has good predictions on the capillary rise of silicone oils covering a wide range of bulk viscosities with the same key parameter W(0), which results from the molecular self-layering. The advantage of the molecular self-layering model over the other models reveals the importance of the layered molecularly thin wetting film ahead of the main meniscus in the energy dissipation associated with dynamic contact angle. The analysis of the capillary rise of silicone oils with a wide range of bulk viscosities provides new insights into the capillary dynamics of polymer melts.

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“…The oscillation energy of the nanoscale silica played an important role in the diffusion of wedge-shaped nanofluids between the oil drop and the glass plates. With decreasing the particle size, the oscillation energy increased, resulting in better nanofluid diffusion at the interface between the oil drop and the solid matrix. − Apparently, the increase in elasticity of microspheres and the inhibition of rapid swelling of the microspheres would be beneficial for efficient profile control and plugging. As inorganic particles generally have high thermal stability and rigidity while organic components have good flexibility, the combination of PAM and inorganic nanoparticles may endow PAM-based hydrogels with improved mechanical properties and enhanced resistances to temperature and salt. , Shamlooh and Hamza prepared SiO 2 –PAM composite hydrogels by combining PAM with SiO 2 and triamine silica, respectively.…”

Section: Introductionmentioning

confidence: 99%

Nanoscale Polyacrylamide Copolymer/Silica Hydrogel Microspheres with High Compressive Strength and Satisfactory Dispersion Stability for Efficient Profile Control and Plugging

Zhao

Lv³

et al. 2021

Ind. Eng. Chem. Res.

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Polyacrylamide (PAM)-based microspheres are commonly used as water plugging and profile control agents, but the poor mechanical strength and few studies on the dispersion stability, both of which are closely related to the profile control performance, limit the application of microspheres. Herein, we synthesize nanoscale PAM-based copolymer hydrogel microspheres with an inverse microemulsion copolymerization of acrylamide (AM) and 2-methyl-2-acrylic amide propyl sulfonic acid (AMPS) in the presence of vinyl-functionalized silica nanoparticles (VSNPs). The results show that a small amount of VSNPs (1.0 wt %) increases the compressive strength of the hydrogel by 0.6 times. The swollen nanoscale PAM/silica hydrogel microspheres show good dispersion stability. VSNPs significantly improve the elasticity of the hydrogel microspheres, and their dispersion stability under high temperature and high-salinity conditions. The simulation evaluation of core plugging suggests that the plugging rate of PAM-based polymer/silica hybrid microspheres with addition of 0.7 wt % VSNPs increases from 80% to 92% compared to neat polymer microspheres. This work provides a novel design of nanoscale cross-linked microspheres for deep profile control in different geological environments.

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The dynamics of capillary-driven two-phase flow: The role of nanofluid structural forces

Cited by 16 publications

References 73 publications

Enhanced Oil Recovery Driven by Nanofilm Structural Disjoining Pressure: Flooding Experiments and Microvisualization

Enhanced Oil Recovery Driven by Nanofilm Structural Disjoining Pressure: Flooding Experiments and Microvisualization

Capillary Rise: Validity of the Dynamic Contact Angle Models

Nanoscale Polyacrylamide Copolymer/Silica Hydrogel Microspheres with High Compressive Strength and Satisfactory Dispersion Stability for Efficient Profile Control and Plugging

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