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936122 Shear-dependent fracture-zone transmissiivity model
348A possible. Increased and better quality data, practical applications of chemical kinetics to inhomogeneous systems, and advances in coupling flow and reaction modelling will further improve geochemical modelling. 90 refs 936120 Propagation of hyperalkaline cement pore waters into the geologic barrier surrounding a radioactive waste repository Eikenberg, J; Lichtner, P C Proc 7th International Symposium on Water-Rock Interaction, Park City, 13-18 July 1992 V1, P377-380. Publ Rotterdam: A A Balkema, 1992
A low to intermediate level waste repository in sedimentary host rocks in planned in Switzerland. Infiltration of groundwater in the near field of the structure could release a hyperalkaline plume into the surrounding rock. A coupled geothermal model (MPATH) is used to investigate alteration of the argillaceous rock under high pH environment and spread of the contaminant plume. Dissolution of quartz and clay minerals and precipitation of feldspars, zeolites, and cement-type phases are predicted. Two examples of alteration of the marl host are evaluated. 936121 Reaction of cement pore fluids with rock: implications for the migration of radionuclides Rochelle, C A; Bateman, K; Milodowski, A E; Noy, D J; Pearce, J; Savage, D; Hughes, C R Proc 7th International Symposium on Water-Rock Interaction, Park City, 13-18 July 1992 V1, P423-426. Publ Rotterdam." A A Balkema, 1992
Cementitious materials will be used extensively in deep disposal of low to intermediate level radioactive waste. In time, saturation with groundwater will occur and the alkaline pore fluid equilibrated with the concrete will advect into the host geology. Escaping radionuclides will migrate through a geosphere conditioned by reaction with the pore fluid. Reactions of common rock-forming minerals with such a pore fluid have been studied by computer modelling and laboratory experiments. Long term effects of the interaction on the ability of the host rock to retard migration of the radionuctides are evaluated.
Permeability and capillarity See also: 936029, 936030, 936275, 936431 936122 Shear-dependent fracture-zone transmissivity model Tannant, D D; Kaiser, P K Can Geotech J V30, NI, Feb 1993, P146-154
A simple flow model based on an en echelon structure for a fracture zone is presented and a phenomenological relation between shear displacement and transmissivity change established. Shear displacements around a circular opening are studied. The greatest shear-induced transmissivity changes occur when a continuous low transmissivity zone is created around the opening. High hydraulic gradients into the opening can then develop. The case of a discontinuous low transmissivity zone is also considered. An alternative mechanism to shearinduced dilation and normal stress-induced fracture closure for description of hydraulic response of fracture zones is provided.
936123 Effect of tunnel excavation on transmissivity distributions and flow in a fracture zone Tannant, D D; Kaiser, P K; Chan, D H Can Geotech J V30, N1, Feb 1993, P155-169
A decrease in fracture zone transmissivity was observed as a tunnel intersected the room 209 fracture zone in the URL. Decrease was greatest as pilot and slash faces proceeded past the fracture zone, and transmissivity recovered towards its original value as excavation progressed. The application of a shear dependent fracture zone transmissivity model developed by Tannant and Kaiser was better able to describe measured response than the conventional normal stress dependent fracture closure model. 936124 Reexamination of the permeability index of clays. Note Babu, G L S; Pandian, N S; Nagaraj, T S Can Geotech J V30, N1, Feb 1993, P187-191
The permeability index (slope of void ratio-coefficient of permeability relation) for sensitive clays can in general be related to 0.5 times the value of initial void ratio. The possibility of obtaining such a relation for Cochin marine clays in terms of liquid limit void ratio is indicated from analysis of published data using a generalised state parameter approach. In principle, these forms of equations for permeability index are tenable, even though they were obtained on the basis of experimental observations alone. 936125 Steam corefloods with concurrent X-ray CT imaging Cuthiell, D; Sedgewick, G; Kissel, G; Wooley, J Can Pet Technoi V32, N3, March 1993, P37-45
A series of laboratory steamflood simulations in sandpacks was carried out, with CT used to monitor online saturation data. Numerical simulation and history matching were used to infer steam relative permeability from the experimental data. Unexpectedly large variations in water saturation transverse to the steam propagation direction were found. These were explained by taking into account small core packing variations, not obvious in CT images, but detected in petrographic image analysis. 936126 Reservoir simulation integrated with geomechanics Tortike, W S; Farouq Ali, S M Can Pet Technoi V32, N5, May 1993, P28-37
In petroleum reservoir simulation it is often necessary to couple fluid flow and heat transfer with the geomechanical behaviour of the reservoir rocks. The assumption of linear elasticity is not adequate. A general coupled reservoir geomechanics model for thermal reservoir modelling is presented. Stress and fuid pressure response to cyclic injection of steam into tar sand, an elastoplastic material, is examined for the coupled and uncoupled cases. Differences are discussed. Changes in porosity obtained with this method are significantly different from those obtained assuming only linear elastic pore compressibility. 936127 Algorithm for transient pressure analysis in arbitrarily shaped reservoirs Yeung, K; Chakrabarty, C Comput Geosci V19, N3, March 1993, P391-397
In many practical situations, reservoir drainage shape is too complicated to be approximated by a circular or rectangular shaped system and relatively simple pressure transient analyses
© 1993 Pergamon Press Ltd. Reproduction not permitted
A low to intermediate level waste repository in sedimentary host rocks in planned in Switzerland. Infiltration of groundwater in the near field of the structure could release a hyperalkaline plume into the surrounding rock. A coupled geothermal model (MPATH) is used to investigate alteration of the argillaceous rock under high pH environment and spread of the contaminant plume. Dissolution of quartz and clay minerals and precipitation of feldspars, zeolites, and cement-type phases are predicted. Two examples of alteration of the marl host are evaluated. 936121 Reaction of cement pore fluids with rock: implications for the migration of radionuclides Rochelle, C A; Bateman, K; Milodowski, A E; Noy, D J; Pearce, J; Savage, D; Hughes, C R Proc 7th International Symposium on Water-Rock Interaction, Park City, 13-18 July 1992 V1, P423-426. Publ Rotterdam." A A Balkema, 1992
Cementitious materials will be used extensively in deep disposal of low to intermediate level radioactive waste. In time, saturation with groundwater will occur and the alkaline pore fluid equilibrated with the concrete will advect into the host geology. Escaping radionuclides will migrate through a geosphere conditioned by reaction with the pore fluid. Reactions of common rock-forming minerals with such a pore fluid have been studied by computer modelling and laboratory experiments. Long term effects of the interaction on the ability of the host rock to retard migration of the radionuctides are evaluated.
Permeability and capillarity See also: 936029, 936030, 936275, 936431 936122 Shear-dependent fracture-zone transmissivity model Tannant, D D; Kaiser, P K Can Geotech J V30, NI, Feb 1993, P146-154
A simple flow model based on an en echelon structure for a fracture zone is presented and a phenomenological relation between shear displacement and transmissivity change established. Shear displacements around a circular opening are studied. The greatest shear-induced transmissivity changes occur when a continuous low transmissivity zone is created around the opening. High hydraulic gradients into the opening can then develop. The case of a discontinuous low transmissivity zone is also considered. An alternative mechanism to shearinduced dilation and normal stress-induced fracture closure for description of hydraulic response of fracture zones is provided.
936123 Effect of tunnel excavation on transmissivity distributions and flow in a fracture zone Tannant, D D; Kaiser, P K; Chan, D H Can Geotech J V30, N1, Feb 1993, P155-169
A decrease in fracture zone transmissivity was observed as a tunnel intersected the room 209 fracture zone in the URL. Decrease was greatest as pilot and slash faces proceeded past the fracture zone, and transmissivity recovered towards its original value as excavation progressed. The application of a shear dependent fracture zone transmissivity model developed by Tannant and Kaiser was better able to describe measured response than the conventional normal stress dependent fracture closure model. 936124 Reexamination of the permeability index of clays. Note Babu, G L S; Pandian, N S; Nagaraj, T S Can Geotech J V30, N1, Feb 1993, P187-191
The permeability index (slope of void ratio-coefficient of permeability relation) for sensitive clays can in general be related to 0.5 times the value of initial void ratio. The possibility of obtaining such a relation for Cochin marine clays in terms of liquid limit void ratio is indicated from analysis of published data using a generalised state parameter approach. In principle, these forms of equations for permeability index are tenable, even though they were obtained on the basis of experimental observations alone. 936125 Steam corefloods with concurrent X-ray CT imaging Cuthiell, D; Sedgewick, G; Kissel, G; Wooley, J Can Pet Technoi V32, N3, March 1993, P37-45
A series of laboratory steamflood simulations in sandpacks was carried out, with CT used to monitor online saturation data. Numerical simulation and history matching were used to infer steam relative permeability from the experimental data. Unexpectedly large variations in water saturation transverse to the steam propagation direction were found. These were explained by taking into account small core packing variations, not obvious in CT images, but detected in petrographic image analysis. 936126 Reservoir simulation integrated with geomechanics Tortike, W S; Farouq Ali, S M Can Pet Technoi V32, N5, May 1993, P28-37
In petroleum reservoir simulation it is often necessary to couple fluid flow and heat transfer with the geomechanical behaviour of the reservoir rocks. The assumption of linear elasticity is not adequate. A general coupled reservoir geomechanics model for thermal reservoir modelling is presented. Stress and fuid pressure response to cyclic injection of steam into tar sand, an elastoplastic material, is examined for the coupled and uncoupled cases. Differences are discussed. Changes in porosity obtained with this method are significantly different from those obtained assuming only linear elastic pore compressibility. 936127 Algorithm for transient pressure analysis in arbitrarily shaped reservoirs Yeung, K; Chakrabarty, C Comput Geosci V19, N3, March 1993, P391-397
In many practical situations, reservoir drainage shape is too complicated to be approximated by a circular or rectangular shaped system and relatively simple pressure transient analyses
© 1993 Pergamon Press Ltd. Reproduction not permitted