Visualisation of Multiphase Fluid Displacement at Pore Scale in Carbonate Media Using X-Ray Microtomography

AbstractThis study focuses on direct numerical simulation of imbibition, displacement of the non-wetting phase by the wetting phase, through water-wet carbonate rocks. We simulate multiphase flow in a limestone and compare our results with high-resolution synchrotron X-ray images of displacement previously published in the literature by Singh et al. (Sci Rep 7:5192, 2017). We use the results to interpret the observed displacement events that cannot be described using conventional metrics such as pore-to-throat aspect ratio. We show that the complex geometry of porous media can dictate a curvature balance that prevents snap-off from happening in spite of favourable large aspect ratios. We also show that pinned fluid-fluid-solid contact lines can lead to snap-off of small ganglia on pore walls; we propose that this pinning is caused by sub-resolution roughness on scales of less than a micron. Our numerical results show that even in water-wet porous media, we need to allow pinned contacts in place to reproduce experimental results.

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Capillary-Dominated Fluid Displacement in Porous Media

Annual Review of Fluid Mechanics ◽

10.1146/annurev-fluid-010518-040342 ◽

2019 ◽

Vol 51 (1) ◽

pp. 429-449 ◽

Cited By ~ 24

Author(s):

Kamaljit Singh ◽

Michael Jung ◽

Martin Brinkmann ◽

Ralf Seemann

Keyword(s):

Porous Media ◽

Pore Space ◽

Contact Angles ◽

Pore Scale ◽

Fluid Displacement ◽

Invasion Pattern ◽

Theoretical Considerations ◽

Displacement Processes ◽

Synchrotron Microtomography ◽

Relevant Material

Liquid invasion into a porous medium is a phenomenon of great importance in both nature and technology. Despite its enormous importance, there is a surprisingly sparse understanding of the processes occurring on the scale of individual pores and of how these processes determine the global invasion pattern. In particular, the exact influence of the wettability remains unclear besides the limiting cases of very small or very large contact angles of the invading fluid. Most quantitative pore-scale experiments and theoretical considerations have been conducted in effectively two-dimensional (2D) micromodels and Hele–Shaw geometries. Although these pioneering works helped to unravel some of the physical aspects of the displacement processes, the relevance of 2D models has not always been appreciated for natural porous media. With the availability of X-ray microtomography, 3D imaging has become a standard for exploring pore-scale processes in porous media. Applying advanced postprocessing routines and synchrotron microtomography, researchers can image even slow flow processes in real time and extract relevant material parameters like the contact angle from the interfaces in the pore space. These advances are expected to boost both theoretical and experimental understanding of pore-scale processes in natural porous media.

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Enhancement of oil recovery by emulsion injection: A pore scale analysis from X-ray micro-tomography measurements

Journal of Petroleum Science and Engineering ◽

10.1016/j.petrol.2020.108134 ◽

2021 ◽

Vol 198 ◽

pp. 108134

Author(s):

Kamila Scheffer ◽

Yves Méheust ◽

Marcio S. Carvalho ◽

Marcos H.P. Mauricio ◽

Sidnei Paciornik

Keyword(s):

Oil Recovery ◽

Scale Analysis ◽

Pore Scale ◽

X Ray ◽

Micro Tomography

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Geochemical controls on wettability alteration at pore-scale during low salinity water flooding in sandstone using X-ray micro computed tomography

Fuel ◽

10.1016/j.fuel.2020.117675 ◽

2020 ◽

Vol 271 ◽

pp. 117675 ◽

Cited By ~ 4

Author(s):

Yongqiang Chen ◽

Nilesh Kumar Jha ◽

Duraid Al-Bayati ◽

Maxim Lebedev ◽

Mohammad Sarmadivaleh ◽

...

Keyword(s):

Computed Tomography ◽

Water Flooding ◽

Wettability Alteration ◽

Pore Scale ◽

Micro Computed Tomography ◽

X Ray ◽

Low Salinity ◽

Low Salinity Water ◽

Geochemical Controls ◽

Salinity Water

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Micro- and macro-scale water retention properties of granular soils: contribution of the X-Ray CT-based voxel percolation method

Soil Research ◽

10.1071/sr18179 ◽

2019 ◽

Vol 57 (6) ◽

pp. 575

Author(s):

Erika Shiota ◽

Toshifumi Mukunoki ◽

Laurent Oxarango ◽

Anne-Julie Tinet ◽

Fabrice Golfier

Keyword(s):

Water Retention ◽

Drainage Water ◽

Transport Processes ◽

Water Retention Curve ◽

Granular Soils ◽

Pore Scale ◽

Micro Computed Tomography ◽

X Ray ◽

Percolation Method ◽

Macro Scale

Water retention in granular soils is a key mechanism for understanding transport processes in the vadose zone for various applications from agronomy to hydrological and environmental sciences. The macroscopic pattern of water entrapment is mainly driven by the pore-scale morphology and capillary and gravity forces. In the present study, the drainage water retention curve (WRC) was measured for three different granular materials using a miniaturised hanging column apparatus. The samples were scanned using X-ray micro-computed tomography during the experiment. A segmentation procedure was applied to identify air, water and solid phases in 3D at the pore-scale. A representative elementary volume analysis based on volume and surface properties validated the experimental setup size. A morphological approach, the voxel percolation method (VPM) was used to model the drainage experiment under the assumption of capillary-dominated quasi-static flow. At the macro-scale, the VPM showed a good capability to predict the WRC when compared with direct experimental measurements. An in-depth comparison with image data also revealed a satisfactory agreement concerning both the average volumetric distributions and the pore-scale local topology. Image voxelisation and the quasi-static assumption of VPM are likely to explain minor discrepancies observed at low suctions and for coarser materials.

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Particle based method and X-ray computed tomography for pore-scale flow characterization in VRFB electrodes

Energy Storage Materials ◽

10.1016/j.ensm.2018.04.021 ◽

2019 ◽

Vol 16 ◽

pp. 91-96 ◽

Cited By ~ 17

Author(s):

Dario Maggiolo ◽

Filippo Zanini ◽

Francesco Picano ◽

Andrea Trovò ◽

Simone Carmignato ◽

...

Keyword(s):

Computed Tomography ◽

Pore Scale ◽

X Ray ◽

Flow Characterization ◽

X Ray Computed

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Direct characterization of solute transport in unsaturated porous media using fast X-ray synchrotron microtomography

Proceedings of the National Academy of Sciences ◽

10.1073/pnas.2011716117 ◽

2020 ◽

Vol 117 (38) ◽

pp. 23443-23449 ◽

Cited By ~ 3

Author(s):

Sharul Hasan ◽

Vahid Niasar ◽

Nikolaos K. Karadimitriou ◽

Jose R. A. Godinho ◽

Nghia T. Vo ◽

...

Keyword(s):

Solute Transport ◽

High Speed ◽

Three Dimensional ◽

Concentration Field ◽

Solute Concentration ◽

Breakthrough Curves ◽

Pore Scale ◽

X Ray ◽

Long Tails ◽

Computed Microtomography

Solute transport in unsaturated porous materials is a complex process, which exhibits some distinct features differentiating it from transport under saturated conditions. These features emerge mostly due to the different transport time scales at different regions of the flow network, which can be classified into flowing and stagnant regions, predominantly controlled by advection and diffusion, respectively. Under unsaturated conditions, the solute breakthrough curves show early arrivals and very long tails, and this type of transport is usually referred to as non-Fickian. This study directly characterizes transport through an unsaturated porous medium in three spatial dimensions at the resolution of 3.25 μm and the time resolution of 6 s. Using advanced high-speed, high-spatial resolution, synchrotron-based X-ray computed microtomography (sCT) we obtained detailed information on solute transport through a glass bead packing at different saturations. A large experimental dataset (>50 TB) was produced, while imaging the evolution of the solute concentration with time at any given point within the field of view. We show that the fluids’ topology has a critical signature on the non-Fickian transport, which yet needs to be included in the Darcy-scale solute transport models. The three-dimensional (3D) results show that the fully mixing assumption at the pore scale is not valid, and even after injection of several pore volumes the concentration field at the pore scale is not uniform. Additionally, results demonstrate that dispersivity is changing with saturation, being twofold larger at the saturation of 0.52 compared to that at the fully saturated domain.

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