Discussion

In the absense of significant geomechanically induced strain in the overburden, a production or injection project will induce changes in rock properties exclusively in the reservoir interval. For this reason, it may be useful to constrain timestrains to be “blocky" using total variation regularization (Steidl et al., 2004; Rudin et al., 1992). Furthermore, amplitude changes between time-lapse seismic images are induced by changes in velocity and density. Changes in velocity can be directly estimated from timeshifts, but density variations are more difficult to estimate. Incorporating the physics of full waveform modeling (Virieux and Operto, 2009) may further constrain the inversion of timeshifts and amplitude weights.