Colloidal-induced permeability degradation assessment of porous media

The paper presents the methodology and results of coreflooding, taking into account the decrease in the permeability caused by the migration of natural colloids during fluid injection. As a porous medium, core samples of consolidated slightly clayey sandstone from one of the oil fields of the Komi Republic (Russia) were used. The coreflooding methodology implied a cyclic change in the injection rate and excluded the influence of other factors such as creep and chemical mobilisation of colloids on permeability. It has been established that a decrease in pore pressure leads to a more intense decrease in permeability during injection, which most likely indicates additional mobilisation of colloids. An analysis of the coreflooding results showed that porous media with lower permeability are more sensitive to colloid migration and pore-pressure changes.