Permeability decline during corefloods with high rates has been widely reported in the literature. It has often been explained by the lifting, migration and subsequent plugging of pores by fine particles, which has been observed in numerous core flood tests. The phenomena have been connected to well productivity impairment during fines production that also has been widely observed in oilfields. The present paper derives formula for skin factor based on the modified particle detachment model with maximum retention function. The fines migration induced skin is shown to increase with increase of rate and initial attached fines concentration.