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Capillary ascension in porous media: a scaling law
18A
PROPERTIES:PERMEABILITY, POROSITY & CAPILLARITY
961140 Dissolution rates of several plutonic rocks and limestone in closed- and batch-system experiments (in Japanese) T. Hirose, T. Hatta & Y. Matsukura, Transactions Japanese Geomorphologicai Union, 16(1), 1995, pp 43-51. A laboratory experiment was carded out to compare the dissolution rates of granite, granodiorite, gabbro, and limestone. Experimental results show the following two conclusions: 1) The dissolution rate is different under different experimental conditions; 2) In the case of coarse grain size, which seems to be closest to field condition, limestone has a high dissolution rate, while gabbro and granodiorite have a medium one, and granite has a low dissolution rate. (from English summary) 961141 Strategies for revegetation of disturbed gravel aeas in climate stressed subarctic environments with special reference to Churchill, Manitoba, Canada: a literature review N. Firlotte & R. J. Staniforth, Climate Research, 5(1), 1995, pp 49-52. In the vicinity of Churchill, Manitoba, Canada, dry heath tundra is restricted to elevated gravel deposits such as beach ridges and eskers. These sites have been utilized for gravel excavation and extraction as well as for building and road construction. When left alone these gravel areas may remain devoid of vegetation for many decades due to the severity of the climate. Nothing has been done to restore them to their pre-disturbance vegetation cover. This paper reviews literature regarding manipulation of chemical and physical properties of gravel substrates in order to facilitate the development of cover by native plants. A planned revegetation project is presented. (from Authors)
Permeability, porosity and capillarity 961142 Imaging the pore structure of geomaterials J. T. Fredrich, B. Menendez & F.-T. Wong, Science, 268(5208), 1995, pp 276-279. Laser scanning confoeal microscopy can be used to image the pore structure of geologic materials in three dimensions at a resolution of 200 nanometers. The technique involves impregnation of the void space with an epoxy doped with a fluorochrome whose fluorescent wavelength matches the excitation wavelength. Optical sections with a thickness of less than 1 micrometer can be sliced from thick polished sections and combined to produce three-dimensional reconstructions. Application of the technique to rocks with porosities from 1 to 20% reveals the geometric complexity of the pore space. The technique can also be applied to other brittle solids such as ceramics. (Authors) 961143 The transport properties of networks of cracks and pores Y. Bernabe, Journal of Geophysical Research, 100(B3), 1995, pp 4231-4241. The heterogeneous nature of the pore space of rocks was numerically simulated by varying the proportions of empty and filled bonds and nodes on a square lattice. A filled bond could contain a tube or a crack or both, the dimensions of which were randomly chosen. For each of 100 network realizations, the permeability, k, electrical formation factor, F, connected porosity, tI,, specific surface area, A, and their pressure dependences were calculated. This large simulated database was then used for testing the validity of several models from the literature. The main result of this work is that permeability was well predicted by the relation K = R2/ (8F), where R is an appropriate length scale. This relation was better satisfied by using the Katz-Thompson (KT) critical radius for R rather than the Schwartz-Sen-Johnson (SSJ) hydraulic radius. (from Author)
961144 Clay microporosity in reservoir sandstones: an application of quantitative electron microscopy in petrophysical evaluation A. Hurst & P. H. Nadeau, American Association of Petroleum Geologists Bulletin, 79(4), 1995, pp 563-573. Clay mineral microporosity in sandstones is measured using computer-assisted image analysis of back-scattered electron micrographs of petrographic sections. Diagenetic kaolinite has a variety of textures with microporosity values ranging from 15 to 61%. Diagenetic chlorite has a generally uniform grain-coating texture and microporosity of about 50%. Analysis of stereo-pair micrographs from scanning-electron microscopy analyses reveals that illite commonly has microporosity of approximately 90%. Clay microporosity data are used to calculate effective pore volumes and volumes of claybound water for clay minerals in sandstones. (from Authors) 961145 Saturated steam relative permeabilities of unconsolidated porous media J. Piquemal, Transport in Porous Media, 17(2), 1994, pp 105120. This paper presents a method and describes an experimental device for determining the steam-water relative permcabilities of unconsolidated porous media. The experimental conditions are as close as possible to those of geothermal reservoirs. The relative permeability have been obtained at 180 and 150°C. Their variations versus liquid saturation are quite classical. The air-water relative permeabilities have been measured also at room temperature. The values obtained under these three conditions are almost identical. However, the air-water relative permeability differs slightly from that of stream at 180 and 150°C. (from Author) 961146 Capillary ascension in porous media: a scaring law J. Bragard & G. Leben, Transport in Porous Media, 16(3), 1994, pp 253-261. A relationship between the microstructure of a porous medium and the height of ascension of a fluid in the material is proposed. The porous medium is modelled by means of a square lattice randomly filled with matter. A scaling law is derived from a numerical simulation. An analytical solution is also obtained and compared with the numerical results. (Authors) 961147 Effect of hydrodynamic forces on capillary pressure and relative permeability R. G. Bentsen, Transport in Porous Media, 17(2), 1994, pp 121-132. In this paper, the idea that the total flux of a given phase may be partitioned into several individual fluxes, together with a new pressure difference equation, is used to explore the possible impact that the hydrodynamic forces might have on capillary pressure and, as a consequence, relative permeability. This reveals that, provided the pressure difference equation is implemented properly, capillarity has no impact on the relative permeability curves for the homogeneous, water-wet porous media considered. Moreover, it is demonstrated that, if the hydrodynamic effects are neglected, very little error is introduced into the analysis. (from Author) 961148 A new method for controlling leaching through permeable channels U. K. Gollapudi, C. L. Knutson, S. S. Bang & M. R. Islam, Chemosphere, 30(4), 1995, pp 695-705. In the environment, natural cementation of geological formations occurs constantly over the geological time due to physical, chemical and biological reactions. Although much attention is devoted to these processes, awareness of microbial involvement in mineral consolidation is quite limited. Mineral precipitation is induced as a result of
PROPERTIES:PERMEABILITY, POROSITY & CAPILLARITY
961140 Dissolution rates of several plutonic rocks and limestone in closed- and batch-system experiments (in Japanese) T. Hirose, T. Hatta & Y. Matsukura, Transactions Japanese Geomorphologicai Union, 16(1), 1995, pp 43-51. A laboratory experiment was carded out to compare the dissolution rates of granite, granodiorite, gabbro, and limestone. Experimental results show the following two conclusions: 1) The dissolution rate is different under different experimental conditions; 2) In the case of coarse grain size, which seems to be closest to field condition, limestone has a high dissolution rate, while gabbro and granodiorite have a medium one, and granite has a low dissolution rate. (from English summary) 961141 Strategies for revegetation of disturbed gravel aeas in climate stressed subarctic environments with special reference to Churchill, Manitoba, Canada: a literature review N. Firlotte & R. J. Staniforth, Climate Research, 5(1), 1995, pp 49-52. In the vicinity of Churchill, Manitoba, Canada, dry heath tundra is restricted to elevated gravel deposits such as beach ridges and eskers. These sites have been utilized for gravel excavation and extraction as well as for building and road construction. When left alone these gravel areas may remain devoid of vegetation for many decades due to the severity of the climate. Nothing has been done to restore them to their pre-disturbance vegetation cover. This paper reviews literature regarding manipulation of chemical and physical properties of gravel substrates in order to facilitate the development of cover by native plants. A planned revegetation project is presented. (from Authors)
Permeability, porosity and capillarity 961142 Imaging the pore structure of geomaterials J. T. Fredrich, B. Menendez & F.-T. Wong, Science, 268(5208), 1995, pp 276-279. Laser scanning confoeal microscopy can be used to image the pore structure of geologic materials in three dimensions at a resolution of 200 nanometers. The technique involves impregnation of the void space with an epoxy doped with a fluorochrome whose fluorescent wavelength matches the excitation wavelength. Optical sections with a thickness of less than 1 micrometer can be sliced from thick polished sections and combined to produce three-dimensional reconstructions. Application of the technique to rocks with porosities from 1 to 20% reveals the geometric complexity of the pore space. The technique can also be applied to other brittle solids such as ceramics. (Authors) 961143 The transport properties of networks of cracks and pores Y. Bernabe, Journal of Geophysical Research, 100(B3), 1995, pp 4231-4241. The heterogeneous nature of the pore space of rocks was numerically simulated by varying the proportions of empty and filled bonds and nodes on a square lattice. A filled bond could contain a tube or a crack or both, the dimensions of which were randomly chosen. For each of 100 network realizations, the permeability, k, electrical formation factor, F, connected porosity, tI,, specific surface area, A, and their pressure dependences were calculated. This large simulated database was then used for testing the validity of several models from the literature. The main result of this work is that permeability was well predicted by the relation K = R2/ (8F), where R is an appropriate length scale. This relation was better satisfied by using the Katz-Thompson (KT) critical radius for R rather than the Schwartz-Sen-Johnson (SSJ) hydraulic radius. (from Author)
961144 Clay microporosity in reservoir sandstones: an application of quantitative electron microscopy in petrophysical evaluation A. Hurst & P. H. Nadeau, American Association of Petroleum Geologists Bulletin, 79(4), 1995, pp 563-573. Clay mineral microporosity in sandstones is measured using computer-assisted image analysis of back-scattered electron micrographs of petrographic sections. Diagenetic kaolinite has a variety of textures with microporosity values ranging from 15 to 61%. Diagenetic chlorite has a generally uniform grain-coating texture and microporosity of about 50%. Analysis of stereo-pair micrographs from scanning-electron microscopy analyses reveals that illite commonly has microporosity of approximately 90%. Clay microporosity data are used to calculate effective pore volumes and volumes of claybound water for clay minerals in sandstones. (from Authors) 961145 Saturated steam relative permeabilities of unconsolidated porous media J. Piquemal, Transport in Porous Media, 17(2), 1994, pp 105120. This paper presents a method and describes an experimental device for determining the steam-water relative permcabilities of unconsolidated porous media. The experimental conditions are as close as possible to those of geothermal reservoirs. The relative permeability have been obtained at 180 and 150°C. Their variations versus liquid saturation are quite classical. The air-water relative permeabilities have been measured also at room temperature. The values obtained under these three conditions are almost identical. However, the air-water relative permeability differs slightly from that of stream at 180 and 150°C. (from Author) 961146 Capillary ascension in porous media: a scaring law J. Bragard & G. Leben, Transport in Porous Media, 16(3), 1994, pp 253-261. A relationship between the microstructure of a porous medium and the height of ascension of a fluid in the material is proposed. The porous medium is modelled by means of a square lattice randomly filled with matter. A scaling law is derived from a numerical simulation. An analytical solution is also obtained and compared with the numerical results. (Authors) 961147 Effect of hydrodynamic forces on capillary pressure and relative permeability R. G. Bentsen, Transport in Porous Media, 17(2), 1994, pp 121-132. In this paper, the idea that the total flux of a given phase may be partitioned into several individual fluxes, together with a new pressure difference equation, is used to explore the possible impact that the hydrodynamic forces might have on capillary pressure and, as a consequence, relative permeability. This reveals that, provided the pressure difference equation is implemented properly, capillarity has no impact on the relative permeability curves for the homogeneous, water-wet porous media considered. Moreover, it is demonstrated that, if the hydrodynamic effects are neglected, very little error is introduced into the analysis. (from Author) 961148 A new method for controlling leaching through permeable channels U. K. Gollapudi, C. L. Knutson, S. S. Bang & M. R. Islam, Chemosphere, 30(4), 1995, pp 695-705. In the environment, natural cementation of geological formations occurs constantly over the geological time due to physical, chemical and biological reactions. Although much attention is devoted to these processes, awareness of microbial involvement in mineral consolidation is quite limited. Mineral precipitation is induced as a result of