Time-lapse parsimonious refraction interferometry: A field experiment

A time-lapse field experiment is conducted to test the effectiveness of parsimonious refraction interferometry for rapidly producing snapshots of subsurface fluid migration in the subsurface. In the field experiment we recorded 90 sparse data sets over a 4.5-hour period of injecting 12-tons of water into the subsurface. The recorded data are then transformed into 90 dense data sets by parsimonious refraction interferometry (PRI). Refraction traveltimes are picked and inverted to generate 90 snapshots of the subsurface velocity distribution. Results show the percolation of water from the ground surface down to a depth of few meters. Here, the P-velocity varies by up to 8% over a 270-minute interval. These snapshots every 3 minutes of rapid velocity changes can be used to estimate the porosity and permeability distributions in the subsurface.