AbstractThe multiphase flow properties of CO2 water systems in permeable rocks control the engineering design and management of industrial CO2 sequestration projects. The relative permeability, capillary pressure, and residual trapping determine the rate of CO2 injection, the spread of injected CO2 in subsurface storage formations, and the long-term immobilization of injected fluid after injection has completed. Due to difficulties in working with CO2 brine systems, however, few observations have been made of these properties at pressure, temperature, and fluid salinities that exist in target reservoirs. In this paper we report on measurements of relative permeability and residual trapping made in a Berea sandstone rock core at reservoir conditions. The drainage relative permeability and residual trapping are characteristic of multiphase flow in a strongly water-wet system.