Study on non-linear seepage flow model for low-permeability reservoir

Abstract

On the basis of the classic capillary model and boundary layer theory,the non-linear seepage flow model for the low-permeability reservoir was established.The density function of throat distribution in Daqing low-permeability reservoir was determined by the constant-rate mercury injection experiment.The non-linear seepage flow model and the throat density distribution function were used to calculate the pressure gradient range of non-linear seepage flow in the low-permeability reservoir.The factors impacting the non-linear seepage flow were also quantitatively analyzed.The results showed that the co-operation of permeability and startup pressure gradient resulted in the non-linear seepage flow.The permeability has greater impact degree and smaller impact range than the startup pressure.