Convection, Dispersion, and Adsorption of Surfactants in Porous Media

1980 ◽  
Vol 20 (06) ◽  
pp. 430-438 ◽  
Author(s):  
W. Fred Ramirez ◽  
Patrick J. Shuler ◽  
Francois Friedman
Keyword(s):  
Porous Media ◽  
Single Phase ◽  
Molecular Diffusion ◽  
Dispersion Coefficient ◽  
Volume Averaging ◽  
Water Soluble ◽  
Mechanical Mixing ◽  
Dead Space Volume ◽  
Mass Dispersion ◽  
Triton X

Abstract Using the theory of volume averaging, we have shown that molecular diffusion, mass tortuosity, and mechanical mixing contribute to the mass-dispersion coefficient. A series of experiments were conducted on the system Triton X-100(TM) surfactant, n-decane oil, and water to determine the contribution of each mechanism to the total-dispersion matrix for flow through fired Berea sandstone. The dynamics of adsorption and the effect of dead-space volume are considered for the single-phase transport of surfactant through fired Berea. A new dynamic asdorption model is developed which considers both mass transfer to the fluid/solid surface and a kinetic surface-adsorption mechanism. Both kinetic adsorption and mass-transfer rate mechanisms are shown to be important over a wide range of injection rates. Introduction It recently has been proposed to inject surfactants into oil-bearing reservoirs to improve the efficiency of the oil recovery process. To understand the effects that surfactants have on the recovery of oil, both the physical and chemical behavior of the oil/surfactant/water interface must be understood in terms of interfacial properties as well as the mass-transport properties of surfactants in porous media. This work presents a systematic study of the physical processes affecting the transport of a surfactant through a porous medium.First, experiments are presented for the determination of the diffusion, tortuosity, and mechanical mixing effects of the dispersion coefficient for both single-phase and two-phase flow in porous media. Finally, adsorption and dead-space volume effects are considered for the single-phase transport of surfactant through fired Berea.The system chosen for study is described as follows. Water Phase. Deionized distilled water was used since its purity ensured constant chemical properties. Oil Phase. Commercial grade n-decane was chosen because it has a low viscosity to ensure a favorable mobility ratio. Solid Phase. The porous medium used in this work was Berea sandstone. The rock was kiln-fired before use to dehydrate and deactivate the clay material. Water Soluble Solutes. Sucrose. It was necessary in some experiments to have tracer solutions with a nonadsorbing solute. Aqueous sucrose solutions were used since they do not interact with either the solid or oil phase. Analysis for concentration was by refractive index. Triton X-100. This commercial nonionic detergent manufactured by Rohm and Haas offered several desirable properties. It is very water-soluble and virtually insoluble in alkane hydrocarbons. In addition, aqueous solutions have been shown to have very little effect on the contact angle on sandstone. Also, the analysis of surfactant concentration can be done conveniently and accurately by ultraviolet spectroscopy. Mass Dispersion Coefficient Using the theory of volume averaging, it has been shown that molecular diffusion D, mass tortuositym, and mechanical mixing F contribute to the mass-dispersion coefficient. K=D(1+ m) + F(v).........................(1) SPEJ P. 430^

scholarly journals The Hydrodynamic Dispersion Characteristics of Coral Sands

2019 ◽  
Vol 7 (9) ◽  
pp. 291 ◽  
Author(s):  
Xiang Cui ◽  
Changqi Zhu ◽  
Mingjian Hu ◽  
Xinzhi Wang ◽  
Haifeng Liu
Keyword(s):  
Particle Size ◽  
Porous Media ◽  
Flow Velocity ◽  
Molecular Diffusion ◽  
Dispersion Coefficient ◽  
Hydrodynamic Dispersion ◽  
Dispersion Characteristics ◽  
Factors Affecting ◽  
Mechanical Dispersion ◽  
Freshwater Aquifers

Dispersion characteristics are important factors affecting groundwater solute transport in porous media. In marine environments, solute dispersion leads to the formation of freshwater aquifers under islands. In this study, a series of model tests were designed to explore the relationship between the dispersion characteristics of solute in calcareous sands and the particle size, degree of compactness, and gradation of porous media, with a discussion of the types of dispersion mechanisms in coral sands. It was found that the particle size of coral sands was an important parameter affecting the dispersion coefficient, with the dispersion coefficient increasing with particle size. Gradation was also an important factor affecting the dispersion coefficient of coral sands, with the dispersion coefficient increasing with increasing d10. The dispersion coefficient of coral sands decreased approximately linearly with increasing compactness. The rate of decrease was −0.7244 for single-grained coral sands of particle size 0.25–0.5 mm. When the solute concentrations and particle sizes increased, the limiting concentration gradients at equilibrium decreased. In this study, based on the relative weights of molecular diffusion versus mechanical dispersion under different flow velocity conditions, the dispersion mechanisms were classified into five types, and for each type, a corresponding flow velocity limit was derived.

The Equations of Motion of Fluids in Porous Media: I. Propagation Velocity of Pressure Pulses

1967 ◽  
Vol 7 (04) ◽  
pp. 333-341 ◽  
Author(s):  
W.R. Foster ◽  
J.M. McMillen ◽  
A.S. Odeh
Keyword(s):  
Porous Media ◽  
Steady Flow ◽  
Single Phase ◽  
Darcy’S Law ◽  
Equations Of Motion ◽  
Volume Averaging ◽  
Momentum Density ◽  
Darcy's Law ◽  
Momentum Balance ◽  
Stream Lines

Abstract The complete equations of average linear momentum balance for a single-phase fluid in an incompressible, homogeneous, porous medium are derived. The derivation begins with Euler's equation of motion /or a continuum and uses an integral transform recently developed by Slattery. For steady flow of compressible, Newtonian fluid, the usual equations of motion result. For transient flow, the space-time description of the pressure is determined in the lowest approximation by the telegrapher's equation. From the analysis a new phenomenological coefficient results which connects the viscous traction to the derivative of the linear momentum density. The magnitude of this coefficient determines the velocity of sound through the pore structure in this approximation to the pressure field. Introduction The modification of Darcy's law of momentum balance for steady, single-phase flow through porous media has been discussed for many years, The first modification was suggested by Forcheimer who added terms of higher order in the velocity. These can be expected to appear because the underlying microscopic equations of momentum balance are themselves nonlinear in the point velocity field. The Reynolds tensor pvv, which represents the convective flux of momentum density, appears in the momentum balance equation. Only in rectilinear flow (parallel stream lines) does the divergence of this tensor vanish. Since the steady flow stream lines in most porous media are not parallel, nonlinear dependence of the pressure gradient on the velocity should naturally appear. This nonlinearity has nothing to do with turbulence in the ordinary sense of random fluctuations in the pressure and velocity fields. It arises simply because the stream lines converge and diverge, even for steady flows. Klinkenberg demonstrated that the permeability coefficient in Darcy's law depends on the absolute pressure or, alternatively, on the density field. however, because he neglected inertial terms of the Forcheimer type, his correction coefficient could not be represented by a constant but tended toward a constant as the velocity decreased. Forcheimer's and Klinkenberg's modifications can be combined in a rigorous way to account for both inertia and slip during steady flow. This will be shown in a future paper. The transient change of pressure in porous media has been described by the diffusion equation. This form results from eliminating the velocity and density fields from a combination of the equations of motion in the form of Darcy's law, the continuity equation and an equation of state. Fatt suggested that the cause of deviations from the prediction of the diffusion equation for pressure transients lies not in the choice of Darcy's law as the equation of motion but on the existence of dead-end pores which might invalidate the averaged equation of continuity. On the other hand, Oroveanu and Pascal noted that the time derivative of the momentum density must be included in the equations of motion since this measures the local rate of change of momentum density. Their differential equation for pressure is the telegrapher's equation (neglecting gravity). However, their form of this equation predicts that the speed of pressure propagation through the pore structure is the same as that through the bulk fluid. M. K. Hubbert attempted a derivation of Darcy's law by volume averaging the Navier-Stokes equations. Since these equations represent momentum balance at a point within an open set of points containing the fluid itself, Hubbert's volume averaging cannot lead to terms involving transfer of momentum between the fluid and the walls of the pores. SPEJ P. 333ˆ

Analysis of process of emulsions transport in hydrophilic/oleophilic granular porous media driven by capillary force

2018 ◽  
Vol 2 (21) ◽  
pp. 85-101
Author(s):  
Olga Shtyka ◽  
Łukasz Przybysz ◽  
Mariola Błaszczyk ◽  
Jerzy P. Sęk
Keyword(s):  
Porous Media ◽  
Experimental Research ◽  
Granular Media ◽  
Single Phase ◽  
Influential Factor ◽  
Dispersed Phase ◽  
Porous Structures ◽  
Phase Concentration ◽  
Granular Porous Media ◽  
Kinetics Of

The research focuses on the issues concerning a process of multiphase liquids transport in granular porous media driven by the capillary pressure. The current publication is meant to introduce the results of experimental research conducted to evaluate the kinetics of the imbibition and emulsions behavior inside the porous structures. Moreover, the influence of the dispersed phase concentration and granular media structure on the mentioned process was considered. The medium imbibition with emulsifier-stabilized emulsions composed of oil as the dispersed phase in concentrations of 10 vol%, 30 vol%, and 50 vol%, was investigated. The porous media consisted of oleophilic/hydrophilic beads with a fraction of 200–300 and 600–800 μm. The experimental results provided that the emulsions imbibition in such media depended stronger on its structure compare to single-phase liquids. The increase of the dispersed phase concentration caused an insignificant mass decreasing of the imbibed emulsions and height of its penetration in a sorptive medium. The concentrations of the imbibed dispersions exceeded their initial values, but reduced with permeants front raise in the granular structures that can be defined as the influential factor for wicking process kinetics.

Dissociation of imino proton(s) of a highly water-soluble metal-free phthalocyanine and determination of its pKa value in water

2013 ◽  
Vol 17 (06n07) ◽  
pp. 447-453 ◽  
Author(s):  
Hiroaki Isago ◽  
Harumi Fujita
Keyword(s):  
Aqueous Media ◽  
Thermal Reaction ◽  
Water Soluble ◽  
Acid Dissociation ◽  
Acid Dissociation Constant ◽  
Metal Free ◽  
Imino Proton ◽  
Pka Value ◽  
Triton X

Dissociation of imino proton(s) in the cavity of the macrocycle of a highly water-soluble, metal-free phthalocyanine ( H 2( H 4 tsppc ); where H 4 tsppc denotes tetrakis{(2′,6′-dimethyl-4′-sulfonic acid)phenoxy}phthalocyaninate) in ethanolic and aqueous solutions has spectrophotometrically been investigated. The spectral changes associated with reaction with NaOH have been found to involve one-proton transfer process in aqueous media while two-protons process in ethanolic media. The acid-dissociation constant of the first imino proton in water (in the presence of Triton X-100) has been determined to be 12.5 ± 0.2 (as pKa) at 25 °C. The doubly deprotonated species in EtOH has been easily converted to its corresponding cobalt(II) derivative by thermal reaction with anhydrous CoCl 2.

scholarly journals Fast Dissolving Electrospun Nanofibers Fabricated from Jelly Fig Polysaccharide/Pullulan for Drug Delivery Applications

Polymers ◽  
2021 ◽  
Vol 13 (2) ◽  
pp. 241
Author(s):  
Thangavel Ponrasu ◽  
Bei-Hsin Chen ◽  
Tzung-Han Chou ◽  
Jia-Jiuan Wu ◽  
Yu-Shen Cheng
Keyword(s):  
Drug Delivery ◽  
Water Vapor Permeability ◽  
Electrospun Nanofibers ◽  
Average Diameter ◽  
Xrd Analysis ◽  
Water Soluble ◽  
Vapor Permeability ◽  
Uv Spectrum ◽  
Sem Images ◽  
Triton X

The fast-dissolving drug delivery systems (FDDDSs) are developed as nanofibers using food-grade water-soluble hydrophilic biopolymers that can disintegrate fast in the oral cavity and deliver drugs. Jelly fig polysaccharide (JFP) and pullulan were blended to prepare fast-dissolving nanofiber by electrospinning. The continuous and uniform nanofibers were produced from the solution of 1% (w/w) JFP, 12% (w/w) pullulan, and 1 wt% Triton X-305. The SEM images confirmed that the prepared nanofibers exhibited uniform morphology with an average diameter of 144 ± 19 nm. The inclusion of JFP in pullulan was confirmed by TGA and FTIR studies. XRD analysis revealed that the increased crystallinity of JFP/pullulan nanofiber was observed due to the formation of intermolecular hydrogen bonds. The tensile strength and water vapor permeability of the JFP/pullulan nanofiber membrane were also enhanced considerably compared to pullulan nanofiber. The JFP/pullulan nanofibers loaded with hydrophobic model drugs like ampicillin and dexamethasone were rapidly dissolved in water within 60 s and release the encapsulants dispersive into the surrounding. The antibacterial activity, fast disintegration properties of the JFP/pullulan nanofiber were also confirmed by the zone of inhibition and UV spectrum studies. Hence, JFP/pullulan nanofibers could be a promising carrier to encapsulate hydrophobic drugs for fast-dissolving/disintegrating delivery applications.

scholarly journals Flow Enhancement of Water-Soluble Polymers through Porous Media by Preshearing

2021 ◽  
Author(s):  
Mohsen Mirzaie Yegane ◽  
Julia Schmidt ◽  
Fatima Dugonjic-Bilic ◽  
Benjamin Gerlach ◽  
Pouyan E. Boukany ◽  
...  
Keyword(s):  
Porous Media ◽  
Water Soluble ◽  
Water Soluble Polymers ◽  
Soluble Polymers ◽  
Flow Enhancement

Shock–like structure of phase-change flow in porous media

1981 ◽  
Vol 104 ◽  
pp. 467-482 ◽  
Author(s):  
L. A. Romero ◽  
R. H. Nilson
Keyword(s):  
Porous Media ◽  
Phase Change ◽  
Single Phase ◽  
Flow In Porous Media ◽  
Two Phase ◽  
Flows In Porous Media ◽  
Dissipative Effects ◽  
Condensing Flows ◽  
Self Similar ◽  
Phase Change Flows

Shock-like features of phase-change flows in porous media are explained, based on the generalized Darcy model. The flow field consists of two-phase zones of parabolic/hyperbolic type as well as adjacent or imbedded single-phase zones of either parabolic (superheated, compressible vapour) or elliptic (subcooled, incompressible liquid) type. Within the two-phase zones or at the two-phase/single-phase interfaces, there may be steep gradients in saturation and temperature approaching shock-like behaviour when the dissipative effects of capillarity and heat-conduction are negligible. Illustrative of these shocked, multizone flow-structures are the transient condensing flows in porous media, for which a self-similar, shock-preserving (Rankine–Hugoniot) analysis is presented.

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