Joint wave-equation inversion of time-lapse seismic data

Joint wave-equation inversion of time-lapse seismic data

Gboyega Ayeni and Biondo Biondi

Abstract:

We discuss two regularized least-squares inversion formulations for time-lapse seismic imaging. Differences in acquisition geometries of baseline and monitor datasets or the presence of a complex overburden can degrade the quality of the time-lapse seismic signature. In such a scenario, the time-lapse amplitude information are poor indicators of the true reservoir property changes. Although the migration operator accurately images the seismic data, it does not remove these amplitude distortions. We pose time-lapse imaging as joint linear inverse problems that utilize concatenations of a target-oriented approximation to the least squares imaging Hessian. In one of the two formulations considered, outputs are inverted time-lapse images, while in the other, outputs are evolving images of the study area. Using a 2D-synthetic sub-salt model, we demonstrate that either joint-inversion formulation can attenuate overburden and geometry artifacts in time-lapse images and that joint wave-equation inversion yields more accurate results than migration or separate inversion.

Joint wave-equation inversion of time-lapse seismic data