Porosity and permeability change during fracture experiments of granite

Abstract

Hot Dry Rock geothermal system can produce energy from previously unusable site, which does not require natural convective hydrothermal resources, and therefore it has large potential as a sustainable power generation. In this system, artificial reservoir is produced by hydro-fracturing in the basement due to water injection, and then water travels through fractures in the rock and inject back into the ground. To test time-scale of water circulation in this system, we investigate porosity and permeability changes during fracture experiments in the laboratory.