Further Development and Studies of Gas Methods in Matrix Diffusion

1993 ◽  
Vol 333 ◽  
Author(s):  
Kari Hartikainen ◽  
K. Väätäinen ◽  
A. Hautojärvi ◽  
J. Timonen
Keyword(s):  
Porous Media ◽  
Numerical Model ◽  
Water Flow ◽  
Present Status ◽  
Gas Flow ◽  
Hydrodynamic Dispersion ◽  
Matrix Diffusion ◽  
Flow Experiment ◽  
Further Development ◽  
Flow Experiments

ABSTRACTThe present status of the recently introduced gas method equipment for migration studies of fractured and porous media is briefly reviewed together with advances in the experimental techniques. The conditions under which matrix diffusion can be observed in both gas flow and water flow experiments are discussed in some detail. Results for a gas flow experiment are shown, and explained with a numerical model which incorporates the effects of hydrodynamic dispersion and matrix diffusion. The necessary parameters for a corresponding water flow experiment are also briefly discussed.

Gas/Water Flow in Porous Media in the Presence of Adsorbed Polymer: Experimental Study on Non-Darcy Effects

2007 ◽  
Vol 10 (04) ◽  
pp. 423-431 ◽  
Author(s):  
Vincent Blanchard ◽  
Didier Lasseux ◽  
Henri Jacques Bertin ◽  
Thierry Rene Pichery ◽  
Guy Andre Chauveteau ◽  
...  
Keyword(s):  
Porous Media ◽  
Water Flow ◽  
Relative Permeability ◽  
Gas Flow ◽  
Water Saturation ◽  
Polymer Adsorption ◽  
Polymer Layer ◽  
Inertial Effects ◽  
Adsorbed Polymer ◽  
Mean Pressure

Summary The objective of this paper is to report some experimental investigations on the effect of polymer adsorption on gas/water flow in non-Darcy regimes in homogeneous porous media, in contrast to previously available analyses focused mainly on the Darcy regime. Our investigation concentrates on gas flow either at low mean pressure, when Klinkenberg effects (or gas slippage) must be considered, or at high flow rates, when inertial effects are significant. The experimental study reported here consists of water and nitrogen injections into various silicon carbide model granular packs having different permeabilities. Experiments are carried out at different water saturations before and after polymer adsorption over flow regimes ranging from slip flow to inertial flow. In good agreement with previous works, in the Darcy regime, we observe an increase in irreducible water saturation and a strong reduction in the relative permeability to water, while the relative permeability to gas is slightly affected. At low mean pressure in the gas phase, the magnitude of the Klinkenberg effect is found to increase with water saturation in the absence of polymer, whereas for the same water saturation, the presence of an adsorbed polymer layer reduces this effect. In the inertial regime, a reduction of inertial effects is observed when gas is injected after polymer adsorption, taking into account water-saturation and permeability modifications. Experimental data are discussed according to hypotheses put forth to explain these effects. Consequences for practical use are also put under prospect. Introduction Water/oil or water/gas flows in porous media are strongly modified in the presence of an adsorbed polymer layer on the pore surface. Several studies, performed in the Darcy regime, showed a phenomenon of disproportionate permeability reduction (DPR). The relative permeability to water (krw) is reduced more than the relative permeability to gas (krg) or to oil (kro). Although this effect was observed over most of the water-soluble polymer/weak gel systems and rock materials, the origin of this effect is still controversial in the literature. Several physical processes have been put forth to explain the selective action of the polymer.Mennella et al. (1998) studied water/oil flows in the presence of an adsorbed polymer layer in random packs of monodisperse spheres. They concluded that the DPR was caused by a swelling/shrinking effect depending on the kind of fluid flowing throughout the packs. They also explained the DPR by pore-scale topological modification (pore-size reduction). Similar studies (Dawe and Zhang 1994; Sparlin and Hagen 1984) were carried out on different systems such as micromodels.Some authors (White et al. 1973; Schneider and Owens 1982; Nilsson et al. 1998) have interpreted the effect of polymer by assuming that a porous medium is composed of separate oil/water pore networks. With this representation, the DPR can be explained by the fact that water permeability is affected by the hydrosoluble polymer present in the pore network occupied by water, while oil permeability is not.Many studies attributed the DPR to a wall effect (Zaitoun and Kohler 1988, 2000; Barreau 1996; Zaitoun et al. 1998), which decreases the pore section accessible to water. The physical origin of this mechanism is adsorption—almost irreversible—on the solid surface. An adsorbed polymer layer on pore walls induces steric hindrance, lubrication effects, and wettability modification, all of which are in favor of a stronger reduction of water permeability than of oil permeability. The physical relevance of this mechanism was tested on numerical simulations at the pore scale (Barreau et al. 1997).Liang and Seright (2000), following Nilsson et al. (1998), proposed to complete the explanation of DPR by a "gel-droplet" model. In this scenario, gel droplets formed in pore bodies cause a higher pressure drop at the pore throat in the wetting phase than in the nonwetting one. These reported studies mainly have been dedicated to the polymer action on oil/water systems, and much less attention has been paid to gas/water flow. However, all available results in this last configuration lead to the same behavior, and the same type of physical explanation (wall effect) was proposed (Zaitoun and Kohler 1989; Zaitoun et al. 1991). If published results dealing with the effect of polymer on permeability reduction observed in the Darcy regime are quite numerous, very little work has been dedicated to the non-Darcy regimes. Elmkies et al. (2002) reported laboratory experimental data showing that adsorbed polymer on natural porous-media cores decreases the inertial effects during gas flow. In this paper, we focus our attention on the influence of adsorbed polymer on gas/water core flow in non-Darcy regimes. Gas injection was performed on unconsolidated cores having different permeabilities, at different water saturations, before and after polymer treatment, and at low mean pressure to investigate Klinkenberg effects, as well as at high flow rates, when inertial effects become important.

A Numerical Model for Water Flow and Chemical Transport in Variably Saturated Porous Media

Ground Water ◽  
1993 ◽  
Vol 31 (4) ◽  
pp. 634-644 ◽  
Author(s):  
T.-C. Jim Yeh ◽  
Rajesh Srivastava ◽  
Amado Guzman ◽  
Thomas Harter
Keyword(s):  
Porous Media ◽  
Numerical Model ◽  
Water Flow ◽  
Chemical Transport ◽  
Saturated Porous Media

GAS EXPANSION-INDUCED ACCELERATION EFFECT OF A HIGHLY COMPRESSIBLE GAS FLOW IN POROUS MEDIA

2015 ◽  
Vol 18 (8) ◽  
pp. 825-834 ◽  
Author(s):  
Hailong Jiang ◽  
M. Chen ◽  
Y. Jin ◽  
K. P. Chen
Keyword(s):  
Porous Media ◽  
Gas Flow ◽  
Flow In Porous Media ◽  
Compressible Gas Flow ◽  
Gas Expansion ◽  
Compressible Gas

Saturated and Unsaturated Water Flow in Inclined Porous Media

2004 ◽  
Vol 9 (2) ◽  
pp. 91-102 ◽  
Author(s):  
Scott W. Weeks ◽  
Graham C. Sander ◽  
Roger D. Braddock ◽  
Chris J. Matthews
Keyword(s):  
Porous Media ◽  
Water Flow ◽  
Unsaturated Water Flow

scholarly journals Pore-Scale Mixing and the Evolution of Hydrodynamic Dispersion in Porous Media

2021 ◽  
Vol 126 (16) ◽  
Author(s):  
Alexandre Puyguiraud ◽  
Philippe Gouze ◽  
Marco Dentz
Keyword(s):  
Porous Media ◽  
Hydrodynamic Dispersion ◽  
Pore Scale

scholarly journals Thermochemical Heat Storage in a Lab-Scale Indirectly Operated CaO/Ca(OH)2 Reactor—Numerical Modeling and Model Validation through Inverse Parameter Estimation

2021 ◽  
Vol 11 (2) ◽  
pp. 682
Author(s):  
Gabriele Seitz ◽  
Farid Mohammadi ◽  
Holger Class
Keyword(s):  
Numerical Model ◽  
Gas Flow ◽  
Reaction Rate ◽  
Heat Storage ◽  
Bulk Material ◽  
Fixed Bed ◽  
Experimental Results ◽  
Fixed Bed Reactor ◽  
Thermochemical Heat Storage ◽  
Speed Up

Calcium oxide/Calcium hydroxide can be utilized as a reaction system for thermochemical heat storage. It features a high storage capacity, is cheap, and does not involve major environmental concerns. Operationally, different fixed-bed reactor concepts can be distinguished; direct reactor are characterized by gas flow through the reactive bulk material, while in indirect reactors, the heat-carrying gas flow is separated from the bulk material. This study puts a focus on the indirectly operated fixed-bed reactor setup. The fluxes of the reaction fluid and the heat-carrying flow are decoupled in order to overcome limitations due to heat conduction in the reactive bulk material. The fixed bed represents a porous medium where Darcy-type flow conditions can be assumed. Here, a numerical model for such a reactor concept is presented, which has been implemented in the software DuMux. An attempt to calibrate and validate it with experimental results from the literature is discussed in detail. This allows for the identification of a deficient insulation of the experimental setup. Accordingly, heat-loss mechanisms are included in the model. However, it can be shown that heat losses alone are not sufficient to explain the experimental results. It is evident that another effect plays a role here. Using Bayesian inference, this effect is identified as the reaction rate decreasing with progressing conversion of reactive material. The calibrated model reveals that more heat is lost over the reactor surface than transported in the heat transfer channel, which causes a considerable speed-up of the discharge reaction. An observed deceleration of the reaction rate at progressed conversion is attributed to the presence of agglomerates of the bulk material in the fixed bed. This retardation is represented phenomenologically by mofifying the reaction kinetics. After the calibration, the model is validated with a second set of experimental results. To speed up the calculations for the calibration, the numerical model is replaced by a surrogate model based on Polynomial Chaos Expansion and Principal Component Analysis.

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