Time Lapse Inversion Workflow Constrained by Reservoir Grid Parameterization

Time lapse seismic provides key information for assisted history matching. Qualitatively geo-bodies extracted from 4D data reflects the front for a given flow event (e.g. the water flood due to an injector). But 4D data can also provide quantitative information relative to dynamic parameters. We propose a novel workflow for quantitative use of geophysical data for AHM which consists in three steps: 1. Model-Based-Inversion which keeps the layer parameterization of the reservoir grid. This parameterization introduces high and low frequencies missing in the seismic bandwidth. 2. Pressure and saturation inversion constrained by dynamic information and handling uncertainty on data and model. 3. Direct mapping of seismically derived information into the reservoir grid (without using any time to depth conversion). That solves the main problem inherent with the vertical change of support from the (regular) seismic grid to the (irregular layer-based) reservoir grid. Our paper is illustrated with real data examples.