New Development of Permeability Profile Modifi-ca tion Tech nique During the 'Ninth Five Year Plan' in Huabei Oilfield

This paper summarizes the types,application and effects of water shutoff agents and the new development of permeability profile modification technique in Huabei Oilfield Company of CNPC.Field application show that water plugging profile modification technique is effective in improving fracture system in reservoirs and oil and water seepage flow in porous medium and in increasing oil output.This technique is especially useful at the late development stage of an oilfield.