资源环境科技发展态势分析平台

We present evidence of permeability enhancement from hydraulic stimulation experiments in fractured crystalline rock. A total of 9.49³ was injected in two fractured intervals of a 300 m long borehole. Repeated Ground Penetrating Radar (GPR) measurements in the same borehole were carried out prior to and following the stimulation. The initial measurements revealed fractures in the vicinity of the borehole that could be traced up to distances of 50 meters away. The data measured post‐stimulation were used in a difference‐imaging approach to illuminate changes in the GPR reflections caused by the stimulations. The changes delineate the enhancement of a large and complex fracture network. These changes likely correspond to changes in local aperture, thus permeability. Our results indicate that borehole GPR yields unique information on subtle changes in hydraulic properties within a relatively large volume and provides a new perspective on the characterization and monitoring of deep geothermal reservoirs.