Monitoring salt tracer transport in granite rock using ground penetrating radar reflection imaging

Investigating preferential flow paths and fractures in rock formations is a crucial task in ongoing research for geothermal reservoir characterization. The work presented here relies on ground penetrating radar (GPR) surveys to monitor salt tracer flow in weakly fractured crystalline rock. Using borehole antennas in single-hole reflection mode an injected tracer is monitored over time by exploiting difference imaging techniques. The study reveals a tracer branching into different flow paths that is in agreement with a simultaneously conducted dye tracer study.