Modelling of Non-Equilibrium Effects in Solvent-Enhanced Spontaneous Imbibition in Fractured Reservoirs

M. Chahardowli[1], R. Farajzadeh[1] , H. Bruining[1]
[1]TU Delft, Delft, The Netherlands

In fractured reservoirs, much of the oil is stored in low permeable matrix blocks that are surrounded by a high permeability fracture network. Therefore, production from fractured reservoir depends on the transfer between fracture and matrix, which is critically dependent on their interaction. COMSOL Multiphysics® was implemented to model the process of penetration of the aqueous phase into an oil-filled core due to both capillary and gravity forces. The theoretical imbibition production curve is faster than the experimental production curve, which implies that the imbibition is occurring much faster than in the experiment. This indicates delayed imbibition, which can in principle be modelled using dynamic capillary pressure and relative permeability effects.