Successful 4D History Matching of the Sleipner CO2 Plume

A simulation model that matches the evolution of the Sleipner CO2 plume as observed in the 2001-, 2004-, 2006-, and 2008 time-lapse seismic data has been developed. The model is based on a thorough interpretation of the intra-sand mudstone layers that constrain the vertical fluid flow. The thickness of each mudstone layer is inferred from baseline seismic amplitudes. Mudstone permeabilities are used as history matching parameters, and the model includes anisotropic sand permeability consistent with the observed dominant flow direction. The flow simulation results are used to generate synthetic time-lapse seismic that is compared to real time-lapse seismic. The results show a good match between simulated and observed CO2 accumulations in terms of areal extent, thickness/amplitude and time-shift between the seismic surveys. Because the model matches the observations without introducing any time-lapse dependent parameters, it may be used to predict the future evolution of the Sleipner CO2 plume.