Abstract: Pucbeng oilfield has entered a high water-cut stage. With more profile control conducted,the profile control effectiveness decreased while the cost increased.Through laboratory test,the modified sludge generated during the process of oilfield development is found to be of the per- formance of profile control agent and then is used as deep profile control agent for oil/water well.In 2006,a large scale of deep profile control was applied in Wei 317 block of Pucheng Oilfield and the result showed it has achieved obvious economic benefits with good stimulation effect and low profile control cost and then proved to be worthy of being greatly popularized.