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Fracture permeability, fluid-rock interactions, EGS
Abstract:
This contribution outlines the protocol, results, and implications of several long-term flow-through experiments conducted with one pure quartz sandstone sample containing a tensile fracture and three slate samples with a saw-cut fracture. Both rock types display very low matrix permeability. The samples were flown through intermittently for 1~4 months at constant temperature and confining pressure. Fracture permeability was determined throughout the experiments, accompanied by a complete ICP-OES chemical analysis of the effluents in defined time intervals. For the slate samples, we also explore the effects of fluid chemistry on permeability changes by flowing with both deionized water and a 0.5 M NaCl solution.