Study of Supercritical CO2 Displacing Water at the Pore Scale and Its Relevance at the Core Scale and Beyond
The advent of carbon sequestration and rapidly decreasing cost of computing creates opportunities in reservoir characterization for carbon storage. Reservoir description has been based on conventional seismic and well-log analysis which may be uncertain in real environments. In recent years, there had been interests in understanding the underlying physics behind multiphase flows in small scales. With the advancement in imaging technology, it is possible to reconstruct real porous media for simulation purposes. All the previous studies have the information gathered at the pore scale and have been limited by the uncertainty of how to use it. Upscaling of such information has always been a topic of great challenge in the fields of geology, hydrogeology, and petroleum engineering. Multiphase lattice Boltzmann method (LBM), a proven tool to simulate flows in porous media, was applied to simulate flows in porous media at the pore scale (above the representative element volume (REV) size threshold) to gather permeability and relative permeability data. Artificially created fields of permeability and relative permeability are used as benchmarks. Cores extracted from these fields were used in kriging to recreate the fields. Pores from the cores were extracted and used as individual data points for kriging. Comparing the core kriged and pore kriged fields showed that while only modest improvements in permeability field accuracy of 4-16% was seen, large accuracy improvements in relative permeability fields of 55-82% was observed.