Angle-dependent time-shift modeling by 3D ray-tracing
Bruno Pereira-Dias, Vitor Leal de Mello, Filipe Borges, Roberto de Melo Dias · Proceeding of the 17th International Congress of the Brazilian Geophysical · 2021
We developed an algorithm to calculate angle-dependent time-shifts with a 3D ray-tracing modeling engine.Two subsurface 4D models helped us evaluating the benefits of the methodology for scenarios of fluid and pressure changes, as well as geomechanical effects in the overburden.The developed algorithm is computationally efficient, and the results show good agreement with crosscorrelation time-shifts from 3D full-wave modeled data.The proposed methodology addresses a major simplification in time-shift interpretation and has the potential to improve 4D studies, in comparison with the standard vertical propagation approach.The mitigation of uncertainties, avoiding interpretation pitfalls, as well as the use of anglestack time-shifts, add up to a more robust interpretation of time-lapse data.