Time-lapse reflection and transmission borehole GPR for saline tracer monitoring in fractures rock

Abstract

Ground Penetrating Radar allows to visualize and analyze flow and transport processes in fractured rocks. Here, we show how data differencing approaches for both, transmission and reflection surveys with borehole antennas, can be used to monitor saline tracer flow in weakly fractured granitic rock. The spatial ambiguity introduced by the radial antenna symmetry was overcome by combining datasets from different boreholes. The tracer signals, found with the two acquisition methods are consistent and allow for flow path reconstruction.