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Fractal Menger Sponge and Sierpinski carpet as models for reservoir rock pore systems: IV. Relationship of fractal dimension to the measured permeability of natural fractal reservoir rocks
77A compacted or quartz cemented reservoir sandstones. The calculation is based on first "principles and is physically rigorous. Its output closely matches permeabilities over a 5 order of magnitude range for Fontainbleau sandstone and predicts pore throat size distributions as measured by mercury porosimetry. Pore-scale geometric features of the model are spatially correlated, not random. Extension to more complex rocks is discussed. 942129 Homogenization analysis of diffusion and adsorption macrotrausport in porous media: macrotrausport in the absence of advection Auriault, J L; Lewandowska, J Geotechnique V43, N3, Sept 1993, P457-469 Governing equations for fluid flow in a porous medium with pollutant diffusion-adsorption are developed. The macroscopic equivalent diffusion tensor and macroscopic governing equations for the average concentration field are deduced by homogenisation. The necessary conditions for this approach to be valid are discussed in terms of the homogenisation parameter, defined as the ratio of scale of pores to the scale of a sample, which can be distinguished in the heterogeneous medium. Conditions under which homogenisation is not possible are specified. The transport mechanisms dominant at different values of homogenisation parameter are examined. 942130 Determination of hydraulic conductivity from complete grainsize distribution curves Alyamani, M; Sen, Z Ground Water V31, N4, July-Aug 1993, P551-555 A range of single, so-called representative grain size distribution parameters has been used in attempts to derive statistical relations between hydraulic conductivity of a depositional medium and grain size distribution. An alternative is presented in which intercept and initial slope of the complete grain size distribution curve are the important parameters. The role of the relatively finer zone of the curve in controlling hydraulic conductivity is discussed. Logical reasoning and empirical data from Saudi Arabia and Australia show the validity of this approach. 942131 Evaluating the volume of porous medium investigated during slug tests Guyonnet, D; Mishra, S; McCord, J Ground Water V31, N4, July-Aug 1993, P627-633 Type curves are developed to allow quantification of the volume of a porous medium investigated during a slug test for cases of an unbounded homogeneous system, a linear constant-head or no-flow boundary, and a radial no-flow boundary. The latter two cases are respectively relevant to fractured media and a formation damaged by the presence of a borehole. The type curves are applicable to design and analysis of slug tests. 942132 Numerical model for water flow and chemical transport in variably saturated porous media Yeh, T C J; Srivastava, R; Guzman, A; Harter, T Ground Water V31, N4, July-Aug 1993, P634-649 A 2D model for flow and transport in the vadose zone is presented. The nonlinear flow equation is solved using the Galerkin finite element techique. A constant velocity field is obtained by separate application of the Galerkin technique to Darcy's equation. Chemical behaviour of the reactive solute is described by a 2-site adsorption-desorption model with a firstRMMS 31t2
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order loss term. The model has been applied to classical flow problems and gives results in excellent agreement with analytical and observed values, even near very sharp fronts. 942133 Modelling coupled heat and contaminant transport in groundwater Hensley, P J; Savvidou, C lnt J Num Anal Meth Geomeeh V17, N7, July 1993, P493527 The mechanisms of coupled heat and fluid transfer in porous media are first discussed. The principles of geotechnical centrifuge modelling are outlined and scaling laws for simulation of contaminant transport from buried sources presented. A model test to simulate 2-dimensional migration from a buried heat and contaminant source is described and results from four runs presented. Experimental data indicate that hydraulic instability is responsible for the transport of contaminant in the soil around the source and that mode of instability is determined by the magnitude of the effective Rayleigh number. 942134 Finite element modelling of three-phase flow in deforming saturated oil reservoirs Lewis, R W; Sukirman, Y Int d Num Anal Meth Geomeeh V17, N8, Aug 1993, P577598 A numerical model for three-dimensional flow of three immiscible fluids in a deforming saturated oil reservoir is presented. The fully coupled governing equations are derived on the basis of Blot's self consistent theory. An elastoplastic soil model with a Mohr-Coulomb failure criterion is used. The equations are solved for fluid pressure and deformation using the finite element method. Compaction and subsidence over a saturated reservoir where free gas exists are examined. 942135 Fractal Menger Sponge and Sierpinski Carpet as models for reservoir rock pore systems: IV. Relationship of fractal dimension to the measured permeability of natural fractal reservoir rocks Garrison, J R; Pearn, W C; von Roscnberg, D U In Situ V17, N3, 1993, P331-362 Fluid flow through a porous rock is controlled by the flow path, which is related to the overall porosity geometry. For a range of natural fractal reservoir rocks, apparent fractal dimension and pore cross-sectional shape factor correlate well with measured permeability, suggesting these parameters are quantitative descriptors of pore geometry and independent of rock type. The validity of these assumptions is examined. For multifractal sandstone pore systems, only the fractal dimension of the large diameter pores is necessary in the empirical equation, suggesting that below some threshold length, pores do not contribute significantly to permeability. 942136 Analysis of porous media heterogeneities using the diffusion of pressure waves Rigord, P; Caristan, Y; Hulin, J P J Geophys Res V98, NB6, June 1993, P9781-9791 An experimental study and a model of diffusion of sinusoidal pressure waves through porous materials are presented. Diffusion effects in homogeneous media and media with percolation-like fractal geometry are first reviewed. Anomalous variations in the media with frequency expected in the latter case are simulated numerically. The results are compared to pressure diffusion data for porous limestones. The complex
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order loss term. The model has been applied to classical flow problems and gives results in excellent agreement with analytical and observed values, even near very sharp fronts. 942133 Modelling coupled heat and contaminant transport in groundwater Hensley, P J; Savvidou, C lnt J Num Anal Meth Geomeeh V17, N7, July 1993, P493527 The mechanisms of coupled heat and fluid transfer in porous media are first discussed. The principles of geotechnical centrifuge modelling are outlined and scaling laws for simulation of contaminant transport from buried sources presented. A model test to simulate 2-dimensional migration from a buried heat and contaminant source is described and results from four runs presented. Experimental data indicate that hydraulic instability is responsible for the transport of contaminant in the soil around the source and that mode of instability is determined by the magnitude of the effective Rayleigh number. 942134 Finite element modelling of three-phase flow in deforming saturated oil reservoirs Lewis, R W; Sukirman, Y Int d Num Anal Meth Geomeeh V17, N8, Aug 1993, P577598 A numerical model for three-dimensional flow of three immiscible fluids in a deforming saturated oil reservoir is presented. The fully coupled governing equations are derived on the basis of Blot's self consistent theory. An elastoplastic soil model with a Mohr-Coulomb failure criterion is used. The equations are solved for fluid pressure and deformation using the finite element method. Compaction and subsidence over a saturated reservoir where free gas exists are examined. 942135 Fractal Menger Sponge and Sierpinski Carpet as models for reservoir rock pore systems: IV. Relationship of fractal dimension to the measured permeability of natural fractal reservoir rocks Garrison, J R; Pearn, W C; von Roscnberg, D U In Situ V17, N3, 1993, P331-362 Fluid flow through a porous rock is controlled by the flow path, which is related to the overall porosity geometry. For a range of natural fractal reservoir rocks, apparent fractal dimension and pore cross-sectional shape factor correlate well with measured permeability, suggesting these parameters are quantitative descriptors of pore geometry and independent of rock type. The validity of these assumptions is examined. For multifractal sandstone pore systems, only the fractal dimension of the large diameter pores is necessary in the empirical equation, suggesting that below some threshold length, pores do not contribute significantly to permeability. 942136 Analysis of porous media heterogeneities using the diffusion of pressure waves Rigord, P; Caristan, Y; Hulin, J P J Geophys Res V98, NB6, June 1993, P9781-9791 An experimental study and a model of diffusion of sinusoidal pressure waves through porous materials are presented. Diffusion effects in homogeneous media and media with percolation-like fractal geometry are first reviewed. Anomalous variations in the media with frequency expected in the latter case are simulated numerically. The results are compared to pressure diffusion data for porous limestones. The complex