Permeability is a key parameter which reflects the seeping capacity of a reservoir.However

reservoir permeability is currently obtained mainly through laboratory core analysis and is confined because of coring and testing cost limits.Other conventional permeability models also have the disadvantage of relatively large errors and can hardly meet the requirements of oil & gas field exploration and development.The pore throat size and distribution of reservoir rocks can be characterized by capillary pressure curves.In most cases

the absolute per-meability of rocks mainly depends on the distribution of pore throats.Based on many previous empirical formu-las

a capillary huddle tube model that simulates ideal pore structure

and the Darcy flow theory

this paper puts forward a formula of reservoir permeability by using intrusive mercury curves.Its application to a sandstone layer of the Upper Devonian in Tarim Basin shows that the predicted and measured permeability coincides well.