Begell House
Journal of Porous Media
Journal of Porous Media
1091-028X
18
8
2015
MACROSCOPIC AND MICROSCOPIC INVESTIGATION OF ALKALINE−SURFACTANT−POLYMER FLOODING IN HEAVY OIL RECOVERY USING FIVE-SPOT MICROMODELS: THE EFFECT OF SHALE GEOMETRY AND CONNATE WATER SATURATION
Plenty of oil reservoirs contain discontinuous shale layers that act as flow barriers. Therefore, understanding their influences on reservoir performance, especially during enhanced oil recovery (EOR) processes, is of great importance. For this purpose, several experiments of water and alkaline−surfactant−polymer (ASP) flooding have been performed on a number of one-quarter five-spot micromodels that contain various configurations of shale layers to simulate shaly porous media. Several features, such as various shale geometrical characteristics and the presence of connate water saturation, were investigated at both macro- and micro-scales. The presence of shales resulted in earlier breakthrough and lower recovery factor due to oil trapping in comparison with the homogenous model (the model with zero shale content). Also, the results illustrate an increase in oil recovery factor with increasing shale orientation (shale angle with mean flow direction), length, distance to producing well, and continuity. On the contrary, increasing shale density (number of shales) and spacing between them caused reduction in oil recovery factor. The effects of connate water saturation on displacement and sweep efficiencies of ASP flooding were also investigated. Several important phenomena relating to the connate water presence were perceived at micro- and macro-scales through analysis of microscopic images in addition to macroscopic examination of the experiments. This study demonstrated the ability of glass micromodel experiments in surveying EOR processes, especially ASP flooding in shaly heavy oil reservoirs, and also visualization of dominated mechanisms occurring at pore scale.
Amin
Mehranfar
Department of Chemical and Petroleum Engineering, Sharif University of Technology, Tehran, Iran
Mohammad Hossein
Ghazanfari
Department of Chemical and Petroleum Engineering, Sharif University of Technology, Tehran, Iran
Mohsen
Masihi
Department of Chemical and Petroleum Engineering, Sharif University of Technology, Tehran, Iran
Davood
Rashtchian
Department of Chemical & Petroleum Engineering, Sharif University of Technology, Tehran, Iran
745-762
MODELING OF GAS LEAKS IN SOILS: A MODERN, SYSTEMATIC APPROACH
In cases involving fires and explosions caused by fugitive natural gas, adequate modeling and quantification of the gas migration process is extremely important, as a properly performed analysis permits the identification and verification of the gas leak path from the leak source to the point of ignition, the quantity of gas that migrated, and the time it took to reach the ignition source. Additionally, a properly made gas flow analysis will provide the calculations and data to rule out other potential gas leak source/sources. This work describes a modern approach for modeling gas migration in soils using the finite element method and combines the solution of the coupled diffusion and seepage equations to describe gas flow in porous media. The methodology employs the open source finite element application Tochnog, which allows multidimensional analysis and both transient and steady state solutions to be found. The method of analysis is validated by comparing the predictions of the model to published data for low-pressure leaks. The solution technique is also applied to a higher-pressure 275,790 Pa (40 psig) gas leak. The methodology proposed also allows calculation of leak flow rate from a known pressure source if the soil composition and distribution are known.
Fernando
Lorenzo
Engineering Systems Inc., 16770 Imperial Valley Dr., Suite 150, Houston, TX 77060, USA
Francisco
Godoy
Engineering Systems Inc., 16770 Imperial Valley Dr., Suite 150, Houston, TX 77060, USA
763-775
RADIATION EFFECT ON NATURAL CONVECTION OVER AN INCLINED WAVY SURFACE EMBEDDED IN A NON-DARCY POROUS MEDIUM SATURATED WITH A NANOFLUID
The effect of radiation on free convection over an inclined wavy surface embedded in a non-Darcy porous medium saturated with nanofluid is studied. A coordinate transformation is used to transform the complex wavy surface to a smooth surface. The governing equations are transformed into a set of ordinary differential equations using similarity transformations and then solved by successive linearization method. The Rosseland approximation is used to describe the radiative heat flux in the energy equation. The present results are compared with previously published work and are found to be in very good agreement. The effects of Grashof number, radiation parameter, Brownian motion parameter, thermophoresis parameter, amplitude of the wavy surface, angle of inclination of the wavy surface on the non-dimensional velocity, temperature, nanoparticle volume fraction, heat, and nanoparticle mass transfer rates are studied and presented graphically.
D.
Srinivasacharya
Department of Mathematics, National Institute of Technology, Warangal-506004,
India
P. Vijay
Kumar
Dept. of Mathematics, National Institute of Technology Warangal-506004, Telangana, India
777-789
CONVECTIVE HEAT TRANSFER AND FLUID FLOW ANALYSIS IN A HELICAL MICROCHANNEL FILLED WITH A POROUS MEDIUM
Forced convection in a helical microchannel heat sink (HMCHS) filled with a porous medium is investigated numerically. The effects of helix radius (0.15−0.30 mm), pitch (0.5−2.0 mm), number of turns (7−10), and aspect ratio (1.5−3.0), toward the heat transfer and fluid flow characteristics are comprehensively investigated. The governing equations for flow and heat transfer are solved using the finite volume method. The results reveal that secondary flow and porous medium can enhance the thermal performance of the HMCHS but is accompanied with an increase in pressure drop.
K.
Narrein
Department of Mechanical Engineering, Faculty of Engineering, University of Malaya, 50603 Kuala Lumpur, Malaysia
Sivanandam
Sivasankaran
King Abdulaziz University
P
Ganesan
Department of Mechanical Engineering, Faculty of Engineering, University of Malaya, 50603 Kuala Lumpur, Malaysia
791-800
HYDROMAGNETIC FLOW NEAR A NON-UNIFORM ACCELERATING PLATE IN THE PRESENCE OF MAGNETIC FIELD THROUGH POROUS MEDIUM
New exact solutions for unsteady magnetohydrodynamic (MHD) flows of a generalized second-grade fluid near a non-uniform accelerating plate have been derived. The generalized second-grade fluid saturates the porous space. Fractional derivative is used in the governing equation. The analytical expressions for velocity and shear stress fields have been obtained by using Laplace transform technique for the fractional calculus. The obtained solutions are expressed in series form in terms of Fox H-functions. Similar solutions for ordinary second-grade fluid passing through a porous space are also recovered. Moreover, several figures are sketched for the pertinent parameters to analyze the characteristics of velocity field and shear stress.
Amir
Khan
Department of Mathematics, University of Malakand, Chakdara, Dir(Lower), Khyber
Pakhtunkhwa, Pakistan; Department of Mathematics and Statistics, University of Swat, Khyber Pakhtunkhwa, Pakistan
Gul
Zaman
Department of Mathematics, University of Malakand, Chakdara, Dir(Lower), Khyber
Pakhtunkhwa, Pakistan
Ghaus
ur Rahman
Department of Mathematics and Statistics, University of Swat, Khyber Pakhtunkhwa, Pakistan
801-809
SURFACE TENSION EFFECTS ON A CONJUGATE LAMINAR FILM-CONDENSATION PROCESS FOR A VERTICAL FIN PLACED IN A POROUS MEDIUM
In this work we treat theoretically the conjugate film-condensation process on a vertical fin embedded in a homogeneous porous medium filled with a saturated vapor. The presence of the solid matrix results in the occurrence of a two-phase flow region governed by gravity and capillarity. In order to predict the influence of surface tension on the condensed thickness, an overall energy balance in the liquid, the two-phase region, and through the fin was conducted. Therefore, the conservation equations of mass, momentum, and energy for the condensed film, together with the energy equation in the fin are reduced to a nonlinear system of two differential equations containing five dimensionless numbers: the Bond number, Bo; the Jakob number, Ja; the Rayleigh number Ra; a conjugate heat transfer parameter, α, which represents the competition between the heat conducted by the fin in the longitudinal direction and the heat conducted through the condensate film, and the aspect ratio of the fin, ε. Using the limit of Ja « 1 with Ra » 1, and finite values of Bo, together with the boundary layer approximation for the film condensation process, the non-dimensional heat transfer or Nusselt number and the overall mass flow rates of the condensed fluid have been obtained as functions of the involved dimensionless parameters.
A.
Hernandez
ESIME Azcapotzalco, Institute Politecnico National, Av. de las Granjas No. 682, Col. Santa Catarina, Del. Azcapotzalco, Mexico, D.F. 02250, Mexico
J.
Arcos
ESIME Azcapotzalco, Institute Politecnico National, Av. de las Granjas No. 682, Col. Santa Catarina, Del. Azcapotzalco, Mexico, D.F. 02250, Mexico
Federico
Mendez
Facultad de Ingenieria, UNAM
Oscar
Bautista
ESIME Azcapotzalco, Institute Politecnico National, Av. de las Granjas No. 682, Col. Santa Catarina, Del. Azcapotzalco, Mexico, D.F. 02250, Mexico
811-823
GAS EXPANSION-INDUCED ACCELERATION EFFECT OF A HIGHLY COMPRESSIBLE GAS FLOW IN POROUS MEDIA
Volume-expansion-induced gas acceleration effect in a highly compressible gas flow in porous media is studied. The importance of gas acceleration is quantified in terms of a dimensionless parameter; conditions under which gas acceleration effect need to be considered in the gas pressure profile and mass flux are identified. It is shown that when the Forchheimer drag is given, the effect of gas acceleration on the gas pressure profile and mass flux depend only on the dimensionless parameter representing the ratio between the gas acceleration and the Forchheimer drag. It is also shown that the Forchheimer drag has an insignificant effect on the outlet pressure in choked flows. The result of this analysis is successfully applied to published experimental data.
Hailong
Jiang
College of Petroleum Engineering, China University of Petroleum (Beijing), Beijing 102200, China
M.
Chen
College of Petroleum Engineering, China University of Petroleum (Beijing), Beijing 102200, China
Y.
Jin
College of Petroleum Engineering, China University of Petroleum (Beijing), Beijing 102200, China
K. P.
Chen
College of Petroleum Engineering, China University of Petroleum (Beijing), Beijing 102200, China ; School for Engineering of Matter, Transport & Energy, Arizona State University, Tempe, Arizona 85287-6106, USA
825-834