Eldert Fokker

PhD Candidate

Which subsurface processes can we monitor using seismic ambient noise? Can we monitor stress or temperature variations? Within research programme DeepNL (NWO) these are some of the questions I try to answer. We derived physics-based relationships between effective stress and seismic velocities, and we validated them in a hydrological context. These relationships enable us to develop a monitoring tool for 4D pore pressure variations in the shallow subsurface (0-200 m) of Groningen, purely based on seismic information. This also implies that it is feasible to passively monitor pore pressure developments in shallow hydrocarbon reservoirs. This physics-based approach can potentially be extended to monitoring of temperature and saturation variations using seismic ambient noise.