Impact of Surface Roughness on Capillary Trapping Using 2D-Micromodel Visualization Experiments

Geistlinger, Helmut; Ataei-Dadavi, Iman; Vogel, Hans‐Jörg

doi:10.1007/s11242-016-0641-y

Cited by 28 publications

(36 citation statements)

References 51 publications

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“…Such films have recently been documented in 2D microfluidic cylinder arrays (Geistlinger et al 2016;Zhao et al 2016) with coarser elements and in a 3D packed bed of spheres (Datta et al 2014). Because of their limited thickness, these films only displace a small fraction of oil and oil saturation decreases only slightly behind the film front.…”

Section: Low Ca Regimementioning

confidence: 99%

“…• ) (e.g., Geistlinger et al 2016;Zhao et al 2016;Krummel et al 2013;Datta et al 2014;Lenormand and Zarcone 1984), in which precursor film flow gives rise to film swelling, snap-off at the pore throats, and subsequent capillary trapping of oil and, accordingly, is associated with high ⟨ s o ⟩ (e.g., Constantinides and Payatakes 2000). The present experiments demonstrate that imbibition can take place even at s ≃ 75…”

Section: Low Ca Regimementioning

confidence: 99%

“…We now compare our low Ca experiment to the classic model for the invasion length, x f (t) , by film flow through grain roughness (Lenormand and Zarcone 1984): where d r is the equivalent roughness diameter; following Geistlinger et al (2016), we replaced with cos a to account for the impact of advancing contact angle, a , on the capillary pressure.…”

Section: Comparison With Precursor Film Flow Theorymentioning

confidence: 99%

“…7b). However, precursor film advances like square root of time through roughness (Geistlinger et al 2016;Lenormand and Zarcone 1984;Hay et al 2008), which suggests that the bulk water front will merge with the precursor film front after sufficient amount of…”

Section: Mean Oil Saturationmentioning

confidence: 99%

“…Microfluidic studies of two-phase, oil/water displacement processes typically involve the addition of dye to the aqueous phase to facilitate visualization (e.g., Geistlinger et al 2016;Frette et al 1997;Chevalier et al 2015;Xu et al 2017;Yun et al 2017;Kumar Gunda et al 2011;Xu et al 2014;Cottin et al 2010;Yeganeh et al 2016;Levaché and Bartolo 2014;Datta et al 2014) unless opaque crude oil is used (e.g., Song and Kovscek 2015;Zhu and Papadopoulos 2012;Bowden et al 2016). However, many enhanced oil recovery and NAPL-remediation approaches involve the addition of chemical additives such as surfactants and polymers to the water that is injected into the system to displace the oil.…”

Section: Introductionmentioning

confidence: 99%

See 4 more Smart Citations

Oil/water displacement in microfluidic packed beds under weakly water-wetting conditions: competition between precursor film flow and piston-like displacement

2018

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Optical microscopy was used to measure depth-averaged oil distribution in a quasi-monolayer of crushed marble packed in a microfluidic channel as it was displaced by water. By calibrating the transmitted light intensity to oil thickness, we account for depth variation in the fluid distribution. Experiments reveal that oil saturation at water breakthrough decreases with increasing Darcy velocity, U w , between capillary numbers Ca = w U w ∕ = 9 × 10 −7 and 9 × 10 −6 , where w is the dynamic viscosity of water and is the oil/water interfacial tension, under the conditions considered presently. In contrast, end-point (long-time) remaining oil saturation depends only weakly on U w . This transient dependence on velocity is attributed to the competition between precursor film flow, which controls early time invasion dynamics but is inefficient at displacing oil, and piston-like displacement, which controls ultimate oil recovery. These results demonstrate that microfluidic experiments using translucent grains and fluids are a convenient tool for quantitative investigation of sub-resolution liquid/liquid displacement in porous media.

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Section: Low Ca Regimementioning

confidence: 99%

Section: Low Ca Regimementioning

confidence: 99%

Section: Comparison With Precursor Film Flow Theorymentioning

confidence: 99%

Section: Mean Oil Saturationmentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

See 3 more Smart Citations

Oil/water displacement in microfluidic packed beds under weakly water-wetting conditions: competition between precursor film flow and piston-like displacement

2018

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Time scales of relaxation dynamics during transient conditions in two‐phase flow

Schlüter

Berg

et al. 2017

Water Resources Research

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The relaxation dynamics toward a hydrostatic equilibrium after a change in phase saturation in porous media is governed by fluid reconfiguration at the pore scale. Little is known whether a hydrostatic equilibrium in which all interfaces come to rest is ever reached and which microscopic processes govern the time scales of relaxation. Here we apply fast synchrotron-based X-ray tomography (X-ray CT) to measure the slow relaxation dynamics of fluid interfaces in a glass bead pack after fast drainage of the sample. The relaxation of interfaces triggers internal redistribution of fluids, reduces the surface energy stored in the fluid interfaces, and relaxes the contact angle toward the equilibrium value while the fluid topology remains unchanged. The equilibration of capillary pressures occurs in two stages: (i) a quick relaxation within seconds in which most of the pressure drop that built up during drainage is dissipated, a process that is to fast to be captured with fast X-ray CT, and (ii) a slow relaxation with characteristic time scales of 1-4 h which manifests itself as a spontaneous imbibition process that is well described by the Washburn equation for capillary rise in porous media. The slow relaxation implies that a hydrostatic equilibrium is hardly ever attained in practice when conducting two-phase experiments in which a flux boundary condition is changed from flow to no-flow. Implications for experiments with pressure boundary conditions are discussed. Plain Language Summary What happens to fluids in a porous medium after pumping is stopped? Fast X-ray tomography shows that even in a sample smaller than a sugar cube fluid interfaces continue to move for hours until an optimal fluid configuration is reached. The pace is limited by slow relaxation of dynamic contact angles. Therefore hydrostatic equilibrium, which is the state at which all fluid interfaces come to rest, is hardly ever attained in practice when conducting two-phase flow experiments where the flow is stopped in much larger soil or rock samples.

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Wettability impact on supercritical CO₂ capillary trapping: Pore‐scale visualization and quantification

Wan

Kim

et al. 2017

Water Resources Research

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How the wettability of pore surfaces affects supercritical (sc) CO2 capillary trapping in geologic carbon sequestration (GCS) is not well understood, and available evidence appears inconsistent. Using a high‐pressure micromodel‐microscopy system with image analysis, we studied the impact of wettability on scCO2 capillary trapping during short‐term brine flooding (80 s, 8–667 pore volumes). Experiments on brine displacing scCO2 were conducted at 8.5 MPa and 45°C in water‐wet (static contact angle θ = 20° ± 8°) and intermediate‐wet (θ = 94° ± 13°) homogeneous micromodels under four different flow rates (capillary number Ca ranging from 9 × 10−6 to 8 × 10−4) with a total of eight conditions (four replicates for each). Brine invasion processes were recorded and statistical analysis was performed for over 2000 images of scCO2 saturations, and scCO2 cluster characteristics. The trapped scCO2 saturation under intermediate‐wet conditions is 15% higher than under water‐wet conditions under the slowest flow rate (Ca ∼ 9 × 10−6). Based on the visualization and scCO2 cluster analysis, we show that the scCO2 trapping process in our micromodels is governed by bypass trapping that is enhanced by the larger contact angle. Smaller contact angles enhance cooperative pore filling and widen brine fingers (or channels), leading to smaller volumes of scCO2 being bypassed. Increased flow rates suppress this wettability effect.

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Impact of Surface Roughness on Capillary Trapping Using 2D-Micromodel Visualization Experiments

Cited by 28 publications

References 51 publications

Oil/water displacement in microfluidic packed beds under weakly water-wetting conditions: competition between precursor film flow and piston-like displacement

Oil/water displacement in microfluidic packed beds under weakly water-wetting conditions: competition between precursor film flow and piston-like displacement

Time scales of relaxation dynamics during transient conditions in two‐phase flow

Wettability impact on supercritical CO₂ capillary trapping: Pore‐scale visualization and quantification

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Impact of Surface Roughness on Capillary Trapping Using 2D-Micromodel Visualization Experiments

Cited by 28 publications

References 51 publications

Oil/water displacement in microfluidic packed beds under weakly water-wetting conditions: competition between precursor film flow and piston-like displacement

Oil/water displacement in microfluidic packed beds under weakly water-wetting conditions: competition between precursor film flow and piston-like displacement

Time scales of relaxation dynamics during transient conditions in two‐phase flow

Wettability impact on supercritical CO2 capillary trapping: Pore‐scale visualization and quantification

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Product

Resources

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Wettability impact on supercritical CO₂ capillary trapping: Pore‐scale visualization and quantification