Simulating migrated and inverted seismic data for enhanced reservoir characterization

Abstract

An optimal use of shared-earth modeling is hampered by the fact that simulating a migrated image that can be compared directly to the real migrated image is time-consuming. The key to enable iterative testing of different geological scenarios is to filter a shared-earth model by a spatial resolution filter to simulate a migrated image. The shared-earth model that describes a target-zone is decoupled from the macro-velocity model that is used to compute the spatial resolution filter and thus enabling iterative testing of different geological scenarios. Synthetic geological models are used to validate that simulated migrated and inverted impedance data can be compared directly to the migrated and inverted impedance real data. An iterative shared-earth modeling approach of the Early Jurassic Cook Formation (Oseberg Field) is used to enhance the reservoir characterization of the Cook Formation (Oseberg Field, Offshore Norway). In the iterative shared-earth modeling approach two different geological scenarios are tested. Relevant wire-line data of the Cook Formation are assigned to the different facies in the earth-model. In order to obtain a closer fit, the size and shape of the facies elements of the geological model are manually varied within the ranges (uncertainties) obtained from a modern-analogue study. Comparison of the simulated migrated and impedance data and real data sets led to the conclusion that east-west migrating channels and tidal sand-bars in an estuarine environment produce the best fitting geological model.