An Improved History-match for Layer Spreading within the Sleipner Plume Including Thermal Propagation Effects

Abstract

The Sleipner CO2 storage operation has been injecting CO2 since 1996, and the growth of the plume has been intensively monitored using time-lapse seismic techniques. Detailed history-matching of the topmost CO2 layer has proven challenging. This paper summarizes results from a series of flow simulations examining two key parameters affecting CO2 mobility: permeability heterogeneity and fluid temperatures within the plume. The best match to the observed distribution of CO2 was achieved by including high permeability channels in the reservoir flow model, as observed on seismic data. Thermal models suggests that CO2 enters the top sand layer 7°C warmer than the ambient reservoir. The resulting reduction in the density and viscosity of CO2 does not significantly improve the fit between seismic and simulation.