From seismic ambient noise to 4D pore pressure monitoring

We previously developed a physics-based model relating changes in pore pressure and vertical stress to seismic velocity variations and validated the model in a small area of Groningen gas field. Using the entire Groningen seismic network, near-surface velocity changes are estimated over a three-year period, using passive image interferometry. Using our developed model, we invert these observations of velocity change for pore pressure variations, and construct a 4D pore pressure model for the shallow subsurface of Groningen. Pressure-head recordings in the southeastern region of Groningen allow us to calibrate our inference tool.