Simulation of Viscous Fingering Phenomenon Using CFD Tools

2014 ◽  
Author(s):  
Diana González ◽  
Miguel Asuaje
Keyword(s):  
Porous Medium ◽  
Porous Media ◽  
Preferential Flow ◽  
Viscous Fingering ◽  
Analytical Models ◽  
Water Mixture ◽  
Ansys Fluent ◽  
Two Fluids ◽  
World Energy ◽  
Flow Through

The world energy crisis requires better and better oil production processes. Oil is stored inside a porous medium in reservoirs several kilometers below the earth’s surface. Over the years, the study and understanding of the physics and fluid phenomena occurring within the porous media have been of great interest. A very common phenomenon within the porous media that has significant impact on production is what is known as viscous fingering. Viscous fingering is an instability that occurs at the interface between two fluids of different viscosity, under certain conditions of speed and pressure, this phenomenon results in undesired production of water together with oil. Experiments and analytical models, trying to reproduce and predict the conditions under which the fingering appears, have extensively studied this phenomenon. The aim of this study is to simulate the phenomenon of viscous fingering using computational fluid dynamics tools. A 2D CFD model of an Oil-Water mixture inside a porous medium using commercial software ANSYS FLUENT v.14 was created. In this model, water enters at a rate of 0.15cm/s to an oil-filled domain. Water drives the oil and forms finger-shaped patterns. It was possible to represent the phenomena using CFD tools. Results show a similar behaviour to that obtained by Brock et al (1991): as fingers grew, they spread transversely, split into smaller fingers, coalesced and blocked the growth of other fingers. It was also observed that water fingers have greater velocity, showing its preferential flow through the formed channels and thus leading to inefficient oil extraction.

Oscillatory forcing of flow through porous media. Part 2. Unsteady flow

2002 ◽  
Vol 465 ◽  
pp. 237-260 ◽  
Author(s):  
D. R. GRAHAM ◽  
J. J. L. HIGDON
Keyword(s):  
Porous Medium ◽  
Porous Media ◽  
Pressure Gradient ◽  
Flow Rate ◽  
Flow Through Porous Media ◽  
Mean Flow ◽  
Two Fluids ◽  
Mean Pressure ◽  
Flow Through ◽  
The Mean

Numerical computations are employed to study the phenomenon of oscillatory forcing of flow through porous media. The Galerkin finite element method is used to solve the time-dependent Navier–Stokes equations to determine the unsteady velocity field and the mean flow rate subject to the combined action of a mean pressure gradient and an oscillatory body force. With strong forcing in the form of sinusoidal oscillations, the mean flow rate may be reduced to 40% of its unforced steady-state value. The effectiveness of the oscillatory forcing is a strong function of the dimensionless forcing level, which is inversely proportional to the square of the fluid viscosity. For a porous medium occupied by two fluids with disparate viscosities, oscillatory forcing may be used to reduce the flow rate of the less viscous fluid, with negligible effect on the more viscous fluid. The temporal waveform of the oscillatory forcing function has a significant impact on the effectiveness of this technique. A spike/plateau waveform is found to be much more efficient than a simple sinusoidal profile. With strong forcing, the spike waveform can induce a mean axial flow in the absence of a mean pressure gradient. In the presence of a mean pressure gradient, the spike waveform may be employed to reverse the direction of flow and drive a fluid against the direction of the mean pressure gradient. Owing to the viscosity dependence of the dimensionless forcing level, this mechanism may be employed as an oscillatory filter to separate two fluids of different viscosities, driving them in opposite directions in the porous medium. Possible applications of these mechanisms in enhanced oil recovery processes are discussed.

Plastic Flow in Confined Porous Media of Complex Contours

1999 ◽  
Author(s):  
Mario F. Letelier ◽  
César E. Rosas
Keyword(s):  
Porous Medium ◽  
Porous Media ◽  
Fluid Flow ◽  
Theoretical Study ◽  
Perturbation Parameter ◽  
Resistance Coefficient ◽  
Boundary Perturbation ◽  
Bingham Plastic ◽  
Flow Through ◽  
Central Plug

Abstract A theoretical study of the fully developed fluid flow through a confined porous medium is presented. The fluid is described by the Bingham plastic model for small values of the yield number. The analysis allows for many admissible shapes of the wall contour. The velocity field is computed for several combination of relevant parameters, i.e., the yield number, Darcy resistance coefficient and the boundary perturbation parameter. The wall effect is especially highlighted and the characteristics of the central plug region as well. Plots of isovel curves and velocity profiles are included for a variety of flow and geometry parameters.

scholarly journals Predicting porosity, permeability, and tortuosity of porous media from images by deep learning

2020 ◽  
Vol 10 (1) ◽  
Author(s):  
Krzysztof M. Graczyk ◽  
Maciej Matyka
Keyword(s):  
Neural Networks ◽  
Porous Medium ◽  
Porous Media ◽  
Deep Learning ◽  
Lattice Boltzmann ◽  
Good Accuracy ◽  
Two Dimensional ◽  
Empirical Estimate ◽  
Flow Through ◽  
Boltzmann Method

AbstractConvolutional neural networks (CNN) are utilized to encode the relation between initial configurations of obstacles and three fundamental quantities in porous media: porosity ($$\varphi$$ φ ), permeability (k), and tortuosity (T). The two-dimensional systems with obstacles are considered. The fluid flow through a porous medium is simulated with the lattice Boltzmann method. The analysis has been performed for the systems with $$\varphi \in (0.37,0.99)$$ φ ∈ ( 0.37 , 0.99 ) which covers five orders of magnitude a span for permeability $$k \in (0.78, 2.1\times 10^5)$$ k ∈ ( 0.78 , 2.1 × 10 5 ) and tortuosity $$T \in (1.03,2.74)$$ T ∈ ( 1.03 , 2.74 ) . It is shown that the CNNs can be used to predict the porosity, permeability, and tortuosity with good accuracy. With the usage of the CNN models, the relation between T and $$\varphi$$ φ has been obtained and compared with the empirical estimate.

scholarly journals New Approach for Determining Tortuosity in Fibrous Porous Media

2010 ◽  
Vol 5 (3) ◽  
pp. 155892501000500 ◽  
Author(s):  
Rahul Vallabh ◽  
Pamela Banks-Lee ◽  
Abdel-Fattah Seyam
Keyword(s):  
Porous Medium ◽  
Porous Media ◽  
Fiber Diameter ◽  
Empirical Relationship ◽  
Air Permeability ◽  
New Approach ◽  
Upper Limits ◽  
Fibrous Porous Media ◽  
Flow Through

A method to determine tortuosity in a fibrous porous medium is proposed. A new approach for sample preparation and testing has been followed to establish a relationship between air permeability and fiberweb thickness which formed the basis for the determination of tortuosity in fibrous porous media. An empirical relationship between tortuosity and fiberweb structural properties including porosity, fiber diameter and fiberweb thickness has been proposed unlike the models in the literature which have expressed tortuosity as a function of porosity only. Transverse air flow through a fibrous porous media increasingly becomes less tortuous with increasing porosity, with the value of tortuosity approaching 1 at upper limits of porosity. Tortuosity also decreased with increase in fiber diameter whereas increase in fiberweb thickness resulted in the increase in tortuosity within the range of fiberweb thickness tested.

scholarly journals Lattice Boltzmann Model for Gas Flow through Tight Porous Media with Multiple Mechanisms

Entropy ◽  
2019 ◽  
Vol 21 (2) ◽  
pp. 133 ◽  
Author(s):  
Junjie Ren ◽  
Qiao Zheng ◽  
Ping Guo ◽  
Chunlan Zhao
Keyword(s):  
Porous Medium ◽  
Porous Media ◽  
Lattice Boltzmann ◽  
Gas Flow ◽  
Stress Sensitivity ◽  
Lattice Boltzmann Model ◽  
Flow Through Porous Media ◽  
Gas Slippage ◽  
Flow Through ◽  
Boltzmann Model

In the development of tight gas reservoirs, gas flow through porous media usually takes place deep underground with multiple mechanisms, including gas slippage and stress sensitivity of permeability and porosity. However, little work has been done to simultaneously incorporate these mechanisms in the lattice Boltzmann model for simulating gas flow through porous media. This paper presents a lattice Boltzmann model for gas flow through porous media with a consideration of these effects. The apparent permeability and porosity are calculated based on the intrinsic permeability, intrinsic porosity, permeability modulus, porosity sensitivity exponent, and pressure. Gas flow in a two-dimensional channel filled with a homogeneous porous medium is simulated to validate the present model. Simulation results reveal that gas slippage can enhance the flow rate in tight porous media, while stress sensitivity of permeability and porosity reduces the flow rate. The simulation results of gas flow in a porous medium with different mineral components show that the gas slippage and stress sensitivity of permeability and porosity not only affect the global velocity magnitude, but also have an effect on the flow field. In addition, gas flow in a porous medium with fractures is also investigated. It is found that the fractures along the pressure-gradient direction significantly enhance the total flow rate, while the fractures perpendicular to the pressure-gradient direction have little effect on the global permeability of the porous medium. For the porous medium without fractures, the gas-slippage effect is a major influence factor on the global permeability, especially under low pressure; for the porous medium with fractures, the stress-sensitivity effect plays a more important role in gas flow.

Lattice-Boltzmann Method for Macroscopic Porous Media Modeling

1998 ◽  
Vol 09 (08) ◽  
pp. 1491-1503 ◽  
Author(s):  
David M. Freed
Keyword(s):  
Porous Medium ◽  
Porous Media ◽  
Lattice Boltzmann Method ◽  
Lattice Boltzmann ◽  
Inertial Effects ◽  
Simulation Region ◽  
Flow Through ◽  
Previous Algorithm ◽  
Validation Tests ◽  
Boltzmann Method

An extension to the basic lattice-BGK algorithm is presented for modeling a simulation region as a porous medium. The method recovers flow through a resistance field with arbitrary values of the resistance tensor components. Corrections to a previous algorithm are identified. Simple validation tests are performed which verify the accuracy of the method, and demonstrate that inertial effects give a deviation from Darcy's law for nominal simulation velocities.

SHOCK PROPAGATION IN A FLOW THROUGH DEFORMABLE POROUS MEDIA: ASYMPTOTIC BEHAVIOUR AS THE POROSITY APPROXIMATES A CONSTANT

2007 ◽  
Vol 17 (08) ◽  
pp. 1261-1278
Author(s):  
ELENA COMPARINI ◽  
MAURA UGHI
Keyword(s):  
Porous Medium ◽  
Porous Media ◽  
Hydraulic Conductivity ◽  
Asymptotic Behaviour ◽  
Incompressible Flow ◽  
Shock Propagation ◽  
One Dimensional ◽  
Deformable Porous Media ◽  
Flux Intensity ◽  
Flow Through

We consider a one-dimensional incompressible flow through a porous medium undergoing deformations such that the porosity and the hydraulic conductivity can be considered as functions of the flux intensity. We prove that if one approximates the porosity with a constant then the solution of the hyperbolic problem converges to the classical continuous Green–Ampt solution, also in the presence of shocks. In general, however, the shocks remain present in any approximating solution.

scholarly journals Numerical study of heat transfer in a porous medium of steel balls

2019 ◽  
Vol 23 (1) ◽  
pp. 271-279
Author(s):  
Mehmet Pamuk
Keyword(s):  
Heat Transfer ◽  
Porous Medium ◽  
Porous Media ◽  
Numerical Study ◽  
Fluid Phase ◽  
Commercial Software ◽  
Number Range ◽  
Unidirectional Flow ◽  
Flow Through ◽  
Steel Balls

In this study, heat transfer in unidirectional flow through a porous medium with the fluid phase being water is analyzed using the commercial software Comsol?. The aim of the study is to validate the suitability of this package for similar problems regarding heat transfer calculations in unidirectional flow through porous media. The porous medium used in the study is comprised of steed balls of 3 mm in diameter filled in a pipe of 51.4 mm inner diameter. The superficial velocity range is 3-10 mm/s which correspond to a Reynolds number range of 150-500 for an empty pipe. Heat is applied peripherally on the outer surface of the pipe at a rate of 7.5 kW/m2 using electrical ribbon heaters. The numerical results obtained using the commercial software Comsol? are compared with those obtained in the experiments once conducted by the author of this article. Results have shown that Comsol? can generate reliable results in heat transfer problems through porous media, provided all parameters are selected correctly, thus making it unnecessary to prepare expensive experimental set-ups and spending extensive time to conduct experiments.

The Mechanism of Gas and Liquid Flow Through Porous Media in the Presence of Foam

1968 ◽  
Vol 8 (04) ◽  
pp. 359-369 ◽  
Author(s):  
L.W. Holm
Keyword(s):  
Porous Medium ◽  
Porous Media ◽  
Liquid Flow ◽  
Effective Permeability ◽  
Mobility Ratio ◽  
Reservoir Rock ◽  
Porous System ◽  
Foam Flow ◽  
Surfactant Solutions ◽  
Flow Through

Abstract This study shows that in the presence of foam, gas and liquid flow separately through porous media representative of reservoir rock. These results were obtained by using tracer techniques to measure the flow of the gas and liquid comprising the foam. Foam does not flow through the porous medium as a body even when the liquid and gas are combined outside the system and injected as foam Instead the liquid and gas forming the foam separate as the foam films break and then re-form in the porous system. Liquid moves through the porous medium via the film network of the bubbles and gas moves progressively through the system by breaking and re-forming bubbles throughout the length of the flow path. The flow rates of the gas and liquid are a function of the number and strength of the films in the porous medium. There is no free flow of gas; i.e., no continuous gas phase. On the basis of these results, foam can be expected to improve a waterflood or gas drive by decreasing the permeability of the reservoir rock to a displacing liquid or gas. This improves the mobility ratio and thus the conformance of the flood. Introduction Foam is formed when gas and a solution of a surface active agent are injected into a porous medium either simultaneously or intermittently. During the past few years, several papers have been published on the subject of foam flow in porous media. Foam has been used successfully in the removal of capillary water blocks from producing formations. The use of foam in gas storage reservoirs to reduce gas leaks and to increase storage capacity has been considered in recent years. Foam has also been investigated as an oil displacing agent, and as an agent to improve the mobility ratio in a waterflood. However, the mechanism by which the gas and liquid phases comprising the foam flow through a porous medium has not been described adequately. Normally, when two immiscible phases (gas and liquid) flow concurrently through a porous medium, each phase follows separate paths or channels. At given saturations of the two phases, a certain number of channels are available to each phase, and as saturations change, the number and configuration of the channels available for each phase also change. The effective permeability of each phase is a function of the saturation of that phase only, and the flow of each phase can be described by Darcy's law. When foam is present, the effective permeability of the porous medium to each phase is greatly reduced compared with permeabilities measured in the absence of foam. Based upon the observed flow of surfactant solutions and gas in capillaries, it has been concluded that the gas and liquid may flow separately or they may flow combined as foam. At least four mechanisms have been postulated to explain how fluids flow with foam present:A large portion of the gas is trapped in the porous medium and a small fraction flows as free gas, following Darcy's law.The foam structure moves as a body; the rate of gas flow is the same as the rate of liquid flow.Gas flows as a discontinuous phase by breaking and re-forming films. Liquid flows as a free phase.A portion of the liquid and gas move as a foam body while excess surfactant solution moves as a free phase. It also has been suggested that different flow mechanisms exist for high quality (dry) foams made from dilute surfactant solutions and for foams made from more concentrated solutions. Studies conducted on the flow of foam through capillaries have shown that a plug-type flow occurs and that foam flows as a body.

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