关键词: 低渗油藏, 非线性渗流, 相对渗透率, 恒速压汞

Abstract: la in low permeability reservoirs.There is obvious nonlinear seepage flow in the low permeability reservoir.The nonlinear seepage flow has effect on the flowing of single phase fluids or two phase fluids.The study of this paper began in the mechanism of nonlinear flow.The throat distribution density function is established by constant rate mercury injection experiment.Combining with the function，based on classic capillary model and boundary layer theory，the nonlinear relative permeability model of low permeability reservoir is established.The core data of Daqing Oilfield is analyzed by the above model.The results illustrate that bigger pressure gradient will result in higher oil relative permeability，lower water relative permeability and slower watercut rate in the range of nonlinear seepage flow pressure gradient.

Key words: low permeability reservoir, non linear seepage flow, relative permeability, constant rate mercury injection