Monitoring of Underground Gas Storage Sites by Elastic 2D Time-lapse Waveform Inversion

Mitigation of anthropogenic green house gas GHG, including CO2 emissions in the atmosphere demand developments of renewable energy resources. However, most renewable energy sources are fluctuating and therefore need energy storage to match power supply and demand. One possible solution is energy geostorage by injecting compressed air in sealed underground structures. After a short introduction to the theory of time-lapse waveform inversion, the theoretical resolution of the isotropic elastic material parameters, as well as the density, will be demonstrated by a synthetic injection scenario using the Marmousi-II model as complex geological background model. Another, more realistic example is based on accurate simulations of the gas migration within a geological simple background model and the use of poroelastic equations to derive suitable effective media parameters.