Making time-domain "warping" applicable to the retrieval of 4D perturbations in depth imaging contexts.

Summary We present a method to address the issue of time-lapse (4D) imaging in complex cases with dipping reservoirs, superimposed reservoirs or complex overburden. The method is based on depth imaging tools, and is faster and more practical than 4D Full Waveform Inversion or more sophisticated, but costly, techniques. The approach is poststack, built on the already existing depth imaging toolbox, and thus enables the valid use of the classical vertical time warping in complex configurations well beyond its original theoretical reach. We explain how our approach makes the warping in (vertical) time work in depth imaging contexts. We establish a proof of concept on synthetic data sets, then show the uplift it brings in two 3D real datasets. As compared to the classical 1D tools, our new approach retrieves 4D perturbations with better resolution, better lateral continuity, and with fewer artifacts, thus facilitating significantly the interpretation.