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Clay linings to landfill sites
224A 934135 Effect of contact area on the permeability of fractures Zimmerman, R W; Chen, D W; Cook, N G W J Hydroi V139, NI/4, Not: 1992, P79-96
voids requirement can be used to monitor the degree of field compaction. Permeability requirements and control of construction are discussed.
Void space geometry is a primary factor affecting fracture hydraulic properties, with a tortuous flow path around contacting asperities being found. An idealised fracture of parallel plates propped open by isolated asperities is considered. Boundary element simulations, electrical conductivity analogues, and effective medium approximations are used to study permeability for circular, elliptical and irregularly shaped asperities. Asperity shape as well as contact area influences permeability.
934140 Permeability of fracture zones in a Precambrian granite Banks, D; Solbjorg, M L; Rohr-Torp, E Q J Engng Geol V25, N4, 1992, P377-388
934136 Fractures: finite-size scaling and multifractais Pyrak-Nolte, L J; Myer, L R; Nolte, D D Pure Appl Geophys V138, N4. 1992, P679-706 A metal injection technique was used to determine contact area and void space in two natural fractures in Stripa granite. A complex geometry of flow paths was revealed, which was analysed using finite-size scaling. At the higher stresses (35 and 88MPa) there is significant size dependence of geometric flow properties at observation scales less than 2mm. This suggests macroscopic flow properties of an extended fracture can be determined on core size specimens. The fracture surfaces have fractal structures which change with applied stress. 934137 Hydro-thermal-mechanical properties of joints in the Carnmeneilis granite Zhao, J; Brown, E T Q J Engng Geol 1/25, N4, 1992, P279-290 Natural and artificial joints were examined in a geothermal rock testing facility at effective normal stresses up to 40MPa, differential pore pressures up to 6MPa and temperatures up to 200 deg C. Observed effective normal stress-closure/permeability relations were fitted by a range of deformation and hydraulic models. The Joint Condition Factor (JCF), which depends on a combination of joint surface geometrical factors, is introduced to explain deviations from smooth parallel plate theory. An empirical relation is proposed between initial aperture, temperature and JRC. 934138 Prediction of permeability of fissured tills Hossain, D Q J Engng Geol V25, N4, 1992, P331-342 Variations in size, orientation and surface condition influence mass permeability and consolidation of Scottish lodgement tills. As an alternative to costly testing of large samples to determine bulk properties, the contribution of discontinuous fissures to flow through a fissured region is examined using finite element analysis. Prediction of mass permeability and its anisotropy is possible using empirical computer-aided models based on observed properties of fissures and intact blocks. Values obtained are in good agreement with large-sample measurements. 934139 Clay linings to landfill sites Murray, E J; Rix, D W; Humphrey, R D Q J Engng Geol V25, N4, 1992, P371-376 Tighter legislative control of landfills is likely. Each site should be individually assessed. The adequacy of a clay for lining use can be indicated using the Moisture Condition Value test (compaction to constant density), whilst the maximum air
Major fracture zones were located by use of aerial photography and seismic methods during site characterisation for the Hvaler tunnel in Norway. Fracture zones were logged during construction and most were found to be filled with secondary clay minerals and to show low transmissivity. Water inflow was mainly from lesser, simpler fractures, not previously identified. Similar experiences have been reported from other tunnels in hard rock, which suggests that remote sensing and geophysics may not be the best technique for location of groundwater in hard rock aquifers. 934141 Simultaneous estimation of relative permeabilities and capillary pressure Chardaire-Riviere, C; Chavent, G; Jaffre, J; Liu, J: Bourbiaux, B J SPE Form Eval V7, N4, Dec 1992, P283-289 A numerical method is presented for simultaneous determination of relative permeability and capillary pressure from results of a single two phase flow test. The experiment is a standard imbibition or drainage displacement with imposed difference of pressure inflow rate. Outlet production, pressure drop between the two faces, and local saturation profiles along the core at different times are necessary input data. Required parameters are estimated using a least squares technique, which has been written as a F O R T R A N code. The method has been validated using synthetic data and laboratory imbibition and drainage experiments. 934142 Estimation of radial permeability distribution from well-test data Oliver, D S SPE Form Eval V7, N4, Dec 1992, P290-296 A method is presented to estimate the radial permeability distribution around a well by back analysis of pressure history. It is illustrated for three problems: permeability variation in a complex reservoir; porosity variation in a complex reservoir; and permeability variation with inaccurate data. Output is seen to be a smoothed version of actual permeability distribution, and an estimate is made of resolution width of the smoothing. Permeability can be estimated without the need to subdivide the rock mass into zones of homogeneous permeability. 934143 Permeability detecraimtion with a n m l ~ formation tester Goode, P A; Thambynayagam, R K M SPE Form Eval V7, N4, Dec 1992, P297-303 In the multiprobe concept, one (sink) probe withdraws fluid from the formation and the resultant pressure transient is measured simultaneously at the sink and observation probes. An analytical model for evaluating permeability is presented which considers a three probe instrument, with one observation probe diametrically opposite the sink and the other vertically above the sink. The effects of various formation parameters on pressure response are examined. Application to a field example is presented.
© 1993 Pergamon Press Ltd. Reproduction not permitted
voids requirement can be used to monitor the degree of field compaction. Permeability requirements and control of construction are discussed.
Void space geometry is a primary factor affecting fracture hydraulic properties, with a tortuous flow path around contacting asperities being found. An idealised fracture of parallel plates propped open by isolated asperities is considered. Boundary element simulations, electrical conductivity analogues, and effective medium approximations are used to study permeability for circular, elliptical and irregularly shaped asperities. Asperity shape as well as contact area influences permeability.
934140 Permeability of fracture zones in a Precambrian granite Banks, D; Solbjorg, M L; Rohr-Torp, E Q J Engng Geol V25, N4, 1992, P377-388
934136 Fractures: finite-size scaling and multifractais Pyrak-Nolte, L J; Myer, L R; Nolte, D D Pure Appl Geophys V138, N4. 1992, P679-706 A metal injection technique was used to determine contact area and void space in two natural fractures in Stripa granite. A complex geometry of flow paths was revealed, which was analysed using finite-size scaling. At the higher stresses (35 and 88MPa) there is significant size dependence of geometric flow properties at observation scales less than 2mm. This suggests macroscopic flow properties of an extended fracture can be determined on core size specimens. The fracture surfaces have fractal structures which change with applied stress. 934137 Hydro-thermal-mechanical properties of joints in the Carnmeneilis granite Zhao, J; Brown, E T Q J Engng Geol 1/25, N4, 1992, P279-290 Natural and artificial joints were examined in a geothermal rock testing facility at effective normal stresses up to 40MPa, differential pore pressures up to 6MPa and temperatures up to 200 deg C. Observed effective normal stress-closure/permeability relations were fitted by a range of deformation and hydraulic models. The Joint Condition Factor (JCF), which depends on a combination of joint surface geometrical factors, is introduced to explain deviations from smooth parallel plate theory. An empirical relation is proposed between initial aperture, temperature and JRC. 934138 Prediction of permeability of fissured tills Hossain, D Q J Engng Geol V25, N4, 1992, P331-342 Variations in size, orientation and surface condition influence mass permeability and consolidation of Scottish lodgement tills. As an alternative to costly testing of large samples to determine bulk properties, the contribution of discontinuous fissures to flow through a fissured region is examined using finite element analysis. Prediction of mass permeability and its anisotropy is possible using empirical computer-aided models based on observed properties of fissures and intact blocks. Values obtained are in good agreement with large-sample measurements. 934139 Clay linings to landfill sites Murray, E J; Rix, D W; Humphrey, R D Q J Engng Geol V25, N4, 1992, P371-376 Tighter legislative control of landfills is likely. Each site should be individually assessed. The adequacy of a clay for lining use can be indicated using the Moisture Condition Value test (compaction to constant density), whilst the maximum air
Major fracture zones were located by use of aerial photography and seismic methods during site characterisation for the Hvaler tunnel in Norway. Fracture zones were logged during construction and most were found to be filled with secondary clay minerals and to show low transmissivity. Water inflow was mainly from lesser, simpler fractures, not previously identified. Similar experiences have been reported from other tunnels in hard rock, which suggests that remote sensing and geophysics may not be the best technique for location of groundwater in hard rock aquifers. 934141 Simultaneous estimation of relative permeabilities and capillary pressure Chardaire-Riviere, C; Chavent, G; Jaffre, J; Liu, J: Bourbiaux, B J SPE Form Eval V7, N4, Dec 1992, P283-289 A numerical method is presented for simultaneous determination of relative permeability and capillary pressure from results of a single two phase flow test. The experiment is a standard imbibition or drainage displacement with imposed difference of pressure inflow rate. Outlet production, pressure drop between the two faces, and local saturation profiles along the core at different times are necessary input data. Required parameters are estimated using a least squares technique, which has been written as a F O R T R A N code. The method has been validated using synthetic data and laboratory imbibition and drainage experiments. 934142 Estimation of radial permeability distribution from well-test data Oliver, D S SPE Form Eval V7, N4, Dec 1992, P290-296 A method is presented to estimate the radial permeability distribution around a well by back analysis of pressure history. It is illustrated for three problems: permeability variation in a complex reservoir; porosity variation in a complex reservoir; and permeability variation with inaccurate data. Output is seen to be a smoothed version of actual permeability distribution, and an estimate is made of resolution width of the smoothing. Permeability can be estimated without the need to subdivide the rock mass into zones of homogeneous permeability. 934143 Permeability detecraimtion with a n m l ~ formation tester Goode, P A; Thambynayagam, R K M SPE Form Eval V7, N4, Dec 1992, P297-303 In the multiprobe concept, one (sink) probe withdraws fluid from the formation and the resultant pressure transient is measured simultaneously at the sink and observation probes. An analytical model for evaluating permeability is presented which considers a three probe instrument, with one observation probe diametrically opposite the sink and the other vertically above the sink. The effects of various formation parameters on pressure response are examined. Application to a field example is presented.
© 1993 Pergamon Press Ltd. Reproduction not permitted