Pore-scale modeling of wettability effects on CO2-brine displacement during geological storage

• Wetting properties of reservoir rocks and caprocks can significantly influence on sequestration of carbon dioxide in deep geological formations. Wettability impacts on the physical and chemical processes that are associated with injecting CO2 underground. Our aim is to understand how wetting properties influence two-phase flow of CO2 and brine in a pore scale domain. We use the phase field method to simulate the two-phase flow of CO2-brine in realistic porous domain geometry. Our focus is on clarifying the pore-scale fluid-fluid displacement mechanisms under different wetting conditions and to quantifying the effect of contact angle on macroscopic parameters such as residual brine saturation, capillary pressure, and specific interfacial area. We could show the phase field method can be applied to a complex porous medium with realistic reservoir permeability. Beside it was shown that it can deal with the conditions with large viscosity contrasts and large wettability (low contact angles) which are difficult to handle with direct numerical approaches. Our simulations results suggest wettability concept cannot be explained just by contact angles. Even though the wettability in pore-scale is defined as the contact angle, there is not any particular relation to link the contact angle to the residual saturations and distribution patterns of CO2 in porous domain. Beside the contact angle, the flow rate and basic properties of fluids which are represent in capillary number and mobility number definitions and also the geometry of porous media are describe the CO2-brine distributions.

Ämnesord

NATURVETENSKAP  -- Geovetenskap och miljövetenskap -- Klimatforskning (hsv//swe)

NATURAL SCIENCES  -- Earth and Related Environmental Sciences -- Climate Research (hsv//eng)

Publikations- och innehållstyp

ref (ämneskategori)

kon (ämneskategori)