Conclusions

Two advanced seismic tools have been presented, namely 3D seismic tomography and poro-elastic modeling. The analysis of the time-lapse North-sea data sets demonstrates the flexibility of tomographic inversion, due to changes in the acquisition geometry and overburden conditions. Analogously, in the case of CO2 injection, time-lapse tomography can be used to evaluate the subtle changes due to the bubble expansion and possible leakage. The pre-stack depth-migrated sections in depth can be subtracted to evaluate the differences in terms of pressure and saturation. Furthermore, the detection of gas-hydrates and free gas offshore Svalbard has shown that poro-elastic modeling is essential to interpret the velocity changes.

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