Application of relative permeability 1.Judge wettability of reservoir for water-wet curve,Swi>20%, intersection water saturation S>50%, and Krw<0.3. for oil-wet curve,Swi<15%,intersection water saturation Sw<50%. there is common characteristics of oil-wet and water-wet for neutral wet.Application of relative permeability 1. Judge wettability of reservoir for water-wet curve, Swi>20%， intersection water saturation Sw>50% ， and Krw<0.3. for oil-wet curve, Swi<15% ，intersection water saturation Sw<50%. there is common characteristics of oil-wet and water-wet for neutral wet