Fig. 5From: Monitoring cold water injections for reservoir characterization using a permanent fiber optic installation in a geothermal production well in the Southern German Molasse BasinSchematic DTS velocity track analysis during injection of cold water. Dark gray and light gray lines are DTS temperature logs (TLog) at different times t1 and t2 and show the downhole propagation of injected cold water in the cased section of a well. Dark blue and light blue lines are DTS profiles at later times t3 and t4 below a feed zone. va and vb are the velocities above and below the hydraulic active zoneBack to article page