4-D SEISMICS, GAS-HYDRATE DETECTION AND OVERPRESSURE PREDICTION AS A COMBINED METHODOLOGY FOR APPLICATION TO CO2 SEQUESTRATION

Abstract

Seismic surveys have proven to be useful for monitoring injected CO2 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.