Roughness of wetting fluid invasion fronts in porous media

1992 ◽  
Vol 69 (26) ◽  
pp. 3731-3734 ◽  
Author(s):  
Shanjin He ◽  
Galathara L. M. K. S. Kahanda ◽  
Po-zen Wong
Keyword(s):  
Porous Media ◽  
Invasion Fronts ◽  
Wetting Fluid

Capillary Impregnation of Viscous Fluids in a Multi-Layered Porous Medium

2019 ◽  
Author(s):  
Shabina Ashraf ◽  
Jyoti Phirani
Keyword(s):  
Porous Medium ◽  
Porous Media ◽  
Oil Recovery ◽  
Viscous Fluids ◽  
Spontaneous Imbibition ◽  
Lab On Chip ◽  
Capillary Impregnation ◽  
Relative Placement ◽  
Homogeneous Porous Medium ◽  
Wetting Fluid

Abstract Capillary impregnation of viscous fluids in porous media is useful in diagnostics, design of lab-on-chip devices and enhanced oil recovery. The impregnation of a wetting fluid in a homogeneous porous medium follows Washburn’s diffusive law. The diffusive dynamics predicts that, with the increase in permeability, the rate of spontaneous imbibition of a wetting fluid also increases. As most of the naturally occurring porous media are composed of hydrodynamically interacting layers having different properties, the impregnation in a heterogeneous porous medium is significantly different from a homogeneous porous medium. A Washburn like model has been developed in the past to predict the imbibition behavior in the layers for a hydrodynamically interacting three layered porous medium filled with a non-viscous resident phase. It was observed that the relative placement of the layers impacts the imbibition phenomena significantly. In this work, we develop a quasi one-dimensional lubrication approximation to predict the imbibition dynamics in a hydrodynamically interacting multi-layered porous medium. The generalized model shows that the arrangement of layers strongly affects the saturation of wetting phase in the porous medium, which is crucial for oil recovery and in microfluidic applications.

Elastic waves in porous media saturated with non-wetting fluid

2020 ◽  
Vol 60 (1) ◽  
pp. 315
Author(s):  
Jimmy X. Li ◽  
Reza Rezaee ◽  
Tobias M. Müller ◽  
Mohammad Sarmadivaleh
Keyword(s):  
Porous Media ◽  
Apparent Viscosity ◽  
Elastic Waves ◽  
Solid Wall ◽  
Seismic Exploration ◽  
Solid Matrix ◽  
Biot Theory ◽  
Bulk Fluid ◽  
Wave Induced ◽  
Wetting Fluid

Elastic waves have widely been used as a non-destructive probing method in oilfield exploration and development, and the most well-known applications are in seismic exploration and borehole sonic logging. For waves in porous media, it is popular to use the Biot theory, which incorporates the wave-induced global flow, accounting for the frictional attenuation. The Biot theory assumes that the fluid is wetting to the solid matrix. However, the fluid is not always wetting the rock in real reservoirs. It was previously revealed that a non-wetting fluid parcel tends to slip on the solid wall pore boundary where the intermolecular potential between the fluid and solid wall is weaker than in wetting fluid conditions. This particular slippage feature means that the coupling relationship between the fluid and solid frame and frictional dissipation is likely to be very different between non-wetting and wetting fluid situations. We characterise this wave-induced slippage using an apparent viscosity for the non-wetting fluid within the thin viscous boundary layer. This apparent viscosity is smaller than the viscosity of the bulk fluid. We demonstrate that the slip correction affects the dynamic permeability and dynamic tortuosity and results in slippage/wettability dependent phase velocities and attenuation of the fully fluid-saturated rock.

scholarly journals Pore-scale mass and reactant transport in multiphase porous media flows

2011 ◽  
Vol 686 ◽  
pp. 40-76 ◽  
Author(s):  
A. Parmigiani ◽  
C. Huber ◽  
O. Bachmann ◽  
B. Chopard
Keyword(s):  
Porous Media ◽  
Penetration Depth ◽  
Reactive Transport ◽  
Scaling Laws ◽  
Fluid Velocity ◽  
Lattice Boltzmann Model ◽  
Pore Scale ◽  
Melting Front ◽  
Capillary Instabilities ◽  
Wetting Fluid

AbstractReactive processes associated with multiphase flows play a significant role in mass transport in unsaturated porous media. For example, the effect of reactions on the solid matrix can affect the formation and stability of fingering instabilities associated with the invasion of a buoyant non-wetting fluid. In this study, we focus on the formation and stability of capillary channels of a buoyant non-wetting fluid (developed because of capillary instabilities) and their impact on the transport and distribution of a reactant in the porous medium. We use a combination of pore-scale numerical calculations based on a multiphase reactive lattice Boltzmann model (LBM) and scaling laws to quantify (i) the effect of dissolution on the preservation of capillary instabilities, (ii) the penetration depth of reaction beyond the dissolution/melting front, and (iii) the temporal and spatial distribution of dissolution/melting under different conditions (concentration of reactant in the non-wetting fluid, injection rate). Our results show that, even for tortuous non-wetting fluid channels, simple scaling laws assuming an axisymmetrical annular flow can explain (i) the exponential decay of reactant along capillary channels, (ii) the dependence of the penetration depth of reactant on a local Péclet number (using the non-wetting fluid velocity in the channel) and more qualitatively (iii) the importance of the melting/reaction efficiency on the stability of non-wetting fluid channels. Our numerical method allows us to study the feedbacks between the immiscible multiphase fluid flow and a dynamically evolving porous matrix (dissolution or melting) which is an essential component of reactive transport in porous media.

scholarly journals Microfluidic Study of Drainage and Imbibition in Porous Media: Definition of Amott Indices

2011 ◽  
Author(s):  
Emilie Dressaire ◽  
Howard A. Stone
Keyword(s):  
Porous Media ◽  
Oil Recovery ◽  
Pressure Difference ◽  
Flow Behavior ◽  
Critical Role ◽  
Rock Surface ◽  
Repeat Units ◽  
Fluid Saturation ◽  
Two Phases ◽  
Wetting Fluid

The wettability of reservoir rocks plays a critical role in oil recovery operations. This property is traditionally defined in terms of the contact angle between the fluid-fluid interface and the solid surface. In natural porous media, it has been preferred to characterize the wettability and its effects on fluid flow behavior in terms of Amott indices, through the capillary pressure-fluid saturation relationship. This “bulk” definition is based on the steady states reached by the two phases, the wetting one and the non-wetting one, upon drainage (removal of the wetting fluid) and imbibition (removal of the non-wetting fluid). These indices provide some indirect indication of the rock surface chemistry and porosity structure. Previous studies on Amott indices have mostly focused on numerical modeling of rocks. In this paper, we present an experimental study on two phase flow in regular lattices of glass microchannels. A wet etching technique is used to fabricate 2D networks composed of hundreds of repeat units. The repeat units are square, hexagonal, or triangular, with a lattice parameter of about 100 micrometers. Controlling and varying the microchannel wettability, network geometry, and fluid properties allow correlating the physical chemistry of the system and the characteristics of the multiphase flow. We perform drainage-imbibition cycles by controlling the pressure difference across the device. For each pressure difference, we record and characterize the distribution of the two phases at equilibrium. Our results capture the dependance of the Amott index on both fluid and network properties. The values obtained are consistent with previous studies on wetting phenomena at the pore level. The drainage-imbibition cycles also provide information on the patterns of invasion. We show that the study of the cycles can further predictability of Amott indices.

scholarly journals Experimental study: Effect of pore geometry and structural heterogeneity on the repetitive two-phase fluid flow in porous media and its implications to PM-CAES

2020 ◽  
Vol 205 ◽  
pp. 07010
Author(s):  
Jingtao Zhang ◽  
Haipeng Zhang ◽  
Donghee Lee ◽  
Sangjin Ryu ◽  
Seunghee Kim
Keyword(s):  
Experimental Study ◽  
Porous Media ◽  
Fluid Flow ◽  
Energy Storage ◽  
Flow Rate ◽  
Structural Heterogeneity ◽  
Pore Geometry ◽  
Two Phase ◽  
Wetting Fluid ◽  
Phase Fluid

Compressed air energy storage in porous media (PM-CAES) has recently been suggested as a promising alternative to existing CAES plants. PM-CAES incurs repetitive two-phase fluid flow caused by the cyclic injection and withdrawal of air to/from the porous medium that is initially saturated with the formation water during the operation. Therefore, predicting the overall macro-scale performance of porous media for energy storage requires a better understanding of repetitive two-phase fluid flow in the pore network at the fundamental pore-scale level. To answer this need, we conducted an experimental study using the microfluidics technology; we constructed polydimethylsiloxane (PDMS)-based micromodels with two different geometries (Type I: circular solids and Type II: square solids) and three different structural heterogeneities (coefficient of variation: COV=0, 0.25 and 0.5). Then, we applied a total of ten injection-withdrawal cycles to each micromodel (i.e., ten cyclic drainage-imbibition processes) at different flow rate conditions (Q=0.01 and 0.1 ml/min). It was observed that the displacement patterns of the initially residing fluid (wetting fluid; oil in this study) and the injected fluid (non-wetting fluid; water in this study) were greatly influenced by the geometry and heterogeneity of the pore structure, and imposed flow rate. Results such as the effective sweep efficiency and residual saturation of the non-wetting fluid were analyzed at each drainage-imbibition cycle to aid in understanding the impact of repetitive fluid flow. The experimental observations imply that the flow rate and structural heterogeneity may influence the efficiency of PM-CAES more than the pore geometry does.

scholarly journals Dos and Don’ts When Developing a System to Investigate Spontaneous Imbibition in Unconsolicdated Porous Media

2019 ◽  
Vol 89 ◽  
pp. 01005 ◽  
Author(s):  
Bergit Brattekås ◽  
Tore L. Føyen ◽  
Trond Vabø ◽  
Håkon Haugland ◽  
Simon I. Reite ◽  
...  
Keyword(s):  
Porous Media ◽  
Oil Recovery ◽  
Fluid Dynamic ◽  
Water Soluble ◽  
Spontaneous Imbibition ◽  
Displacement Front ◽  
Wide Range ◽  
Unconsolidated Porous Media ◽  
The Impact ◽  
Wetting Fluid

This paper describes the development of a consistent model system to measure spontaneous imbibition and determine saturation functions in unconsolidated porous media. Sand grains or glass beads were packed in up to 0.5 m long, transparent glass tubes with optical access to local saturation development during spontaneous imbibition processes. The Two Ends Open-Free spontaneous imbibition (TEOFSI) boundary condition was used, where one end face is exposed to the wetting fluid and the other end to the non-wetting fluid. Dynamic measurement of the advancing displacement front and volumetric production from each open end-face enabled estimation of capillary pressure and relative permeability for the system. A range of wetting- and non-wetting phase viscosities and viscosity ratios was used during spontaneous imbibition in unconsolidated sand or glass packs. Wetting phase (water) viscosity was increased using water soluble glycerol or polymers. Air or mineral oil of varying composition provided a wide range of non-wetting phase viscosities. High permeable systems are extremely sensitive to laboratory properties, which may dominate the viscous resistance and determine flow behaviour. Systematic discrepancies observed in early testing indicated that end effects were present, even in long systems, in the filters at each end of the glass tube to maintain the grains or beads in place. Different filters were tested (no filter, glass, paper and micro-porous discs) to determine the impact of the filter on spontaneous imbibition. In addition to slower oil recovery than anticipated, developmentof a non-uniform displacement front was observed, demonstrating the large influence from minute heterogeneities within the packs, and at the end faces. A standard sand grain packing procedure, using a custom-designed packing device, was therefore developed to ensure homogeneous properties throughout theporous media, and limited the spread in porosity and permeability values. Homogeneous sand packs with reproducible properties are necessary, to systematically investigate flow parameters and changes in wettability in unconsolidated porous media.

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