Micro Time-Lapse - Preliminary Results

This work presents preliminary theoretical and experimental results of a new seismic exploration method that can be used as Direct Hydrocarbon Indicator (DHI). It is based on inelastic attenuation and uses a dual field of seismic waves. By theoretically computing the composite deformation induced by a history loading of stress, it is observed that the second step stress comes across a different mechanical configuration than the first. This may imply that both pulses may propagate with different velocities in the dynamic case, a situation that will not occur in perfectly elastic media. This can be used to detect subsurface anomalies such as fractured or high porosity zones that may be associated to the presence of hydrocarbons. While the procedure to obtain the creep compliance in the case of multiple sequential loading may not be as accurate, it provides a good estimate of what may be happening within the reservoir rocks. The next step, which is currently underway, is to carry out similar studies in an acoustic laboratory using band-limited signals.