The Cobourg limestone is a very low porosity rock consisting of lighter nodular regions that are predominantly calcite and darker regions consisting of calcite,quartz,dolomite,and an appreciable clay fraction.This pap...The Cobourg limestone is a very low porosity rock consisting of lighter nodular regions that are predominantly calcite and darker regions consisting of calcite,quartz,dolomite,and an appreciable clay fraction.This paper presents the application of the theory of multi-phasic composites to estimate the possible maximum effective thermal conductivity of the heterogeneous rocks.The thermal conductivity estimates are expected to be representative of the intact rock,without fractures or fissures that can influence the heat conduction process.The estimates are therefore indicative of the thermal properties of the rock in undisturbed regions unaffected by the influences of stress relief and excavation damage during construction of deep ground repositories for the disposal of heat-emitting nuclear waste.展开更多
Argillaceous limestone formations are being proposed as sites suitable for constructing a deep geologic repository for storing low-to intermediate-level nuclear waste in southern Ontario, Canada. The Cobourg limestone...Argillaceous limestone formations are being proposed as sites suitable for constructing a deep geologic repository for storing low-to intermediate-level nuclear waste in southern Ontario, Canada. The Cobourg limestone is characterized by a visual appearance of heterogeneity resulting from light gray calcite nodular regions interspersed with dark gray calcite-dolomite-quartz partings containing a clay component. This paper presents the results of experiments conducted to determine the permeability of both the light gray and the dark gray species of the Cobourg limestone. The permeabilities were successfully estimated from both steady state and hydraulic pulse tests conducted using specially designed miniature water entry ports, which were epoxied to the surface of the rock sample containing cavities drilled into the rock species of interest. The results show that the dark gray species of the Cobourg limestone has a permeability that is roughly one order of magnitude greater than the light gray calcite species.展开更多
文摘The Cobourg limestone is a very low porosity rock consisting of lighter nodular regions that are predominantly calcite and darker regions consisting of calcite,quartz,dolomite,and an appreciable clay fraction.This paper presents the application of the theory of multi-phasic composites to estimate the possible maximum effective thermal conductivity of the heterogeneous rocks.The thermal conductivity estimates are expected to be representative of the intact rock,without fractures or fissures that can influence the heat conduction process.The estimates are therefore indicative of the thermal properties of the rock in undisturbed regions unaffected by the influences of stress relief and excavation damage during construction of deep ground repositories for the disposal of heat-emitting nuclear waste.
基金supported by NSERC Discoverythe studentship support provided by a McGill Engineering Doctoral Award, FQRNT and the SAAQ
文摘Argillaceous limestone formations are being proposed as sites suitable for constructing a deep geologic repository for storing low-to intermediate-level nuclear waste in southern Ontario, Canada. The Cobourg limestone is characterized by a visual appearance of heterogeneity resulting from light gray calcite nodular regions interspersed with dark gray calcite-dolomite-quartz partings containing a clay component. This paper presents the results of experiments conducted to determine the permeability of both the light gray and the dark gray species of the Cobourg limestone. The permeabilities were successfully estimated from both steady state and hydraulic pulse tests conducted using specially designed miniature water entry ports, which were epoxied to the surface of the rock sample containing cavities drilled into the rock species of interest. The results show that the dark gray species of the Cobourg limestone has a permeability that is roughly one order of magnitude greater than the light gray calcite species.
