Post‐stack versus pre‐stack stratigraphic inversion for CO 2 monitoring purposes: A case study for the saline aquifer of the Sleipner field

Abstract

For a decade post‐stack stratigraphic inversion has been extended to pre‐stack inversion with definite success. The main interest is to optimize elastic parameters such as P‐wave and S‐wave impedances instead of acoustic impedances only. The aim of our study is to evaluate the efficiency of the pre‐stack stratigraphic inversion over the Sleipner saline aquifer, which is used for massive storage. Another aspect of our work is to compare the potential of our pre‐stack and post‐stack inversions. In both cases we use the same methodology. Only the model parameterization is different in the optimization problem. On the one hand the encouraging result of our pre‐stack inversion allowed us to compare acoustic and elastic P‐wave impedances. On the other hand, we compare the 3D distribution of P‐ and S‐impedances in the plume, which are crucial attributes for both reservoir characterization and monitoring.