Ray-based time-lapse traveltime tomography

Abstract

Until very recently, ray-based time-lapse traveltime tomography algorithms were scarce and limited, in opposition to electric resistance tomography (ERT) where multiple approaches have been developed over the last two decades. In this paper, three time-lapse ERT schemes are adapted for traveltime tomography. We show using synthetic crosswell data that the time-lapse algorithms allow reducing artifacts compared to independent inversions. Moreover, schemes relying on a reference model to regularize the inversion provide the best results.