4-D SEISMICS, GAS-HYDRATE DETECTION AND OVERPRESSURE PREDICTION AS A COMBINED METHODOLOGY FOR APPLICATION TO CO_2 SEQUESTRATION

摘要

Seismic surveys have proven to be useful for monitoring injected CO_2 in the subsurface. In this work, we show how rock physics, poro-elastic modeling and 3D seismic tomography can be combined to detect the subtle changes in seismic properties related to changes in pore-fill. 3D seismic tomography yields the P- and S-wave velocity cubes, which are converted to petro-physical properties by using rock-physics models of partial saturation under varying temperature and pressure conditions, and seismic numerical modeling. The methodology is illustrated with field examples of time-lapse analysis and gas-hydrate detection.