Abstract For long, early water breakthrough has been a major concern for the operators during the life of a waterflood. Early breakthroughs can result in large quantities of produced water and consequently increase the overall cost per barrel of produced oil. In more severe cases, this can result in premature shut-in of wells. The oil and gas industry has developed a host of technologies to improve the sweep efficiency of waterfloods. These methods include the use of certain injection/production patterns, drilling horizontal and deviated wells, use of special chemicals as well as inflow control devices (ICDs). The purpose of the first two methods is to create an even movement of injection fluid across the reservoir. Special chemicals have been used to divert the injected fluid to eliminate channeling and to improve sweep efficiency. Inflow control devices have been used to delay water or gas breakthrough, making possible a more efficient drainage of the reservoir while maximizing recovery. The technique presented in this work involves creating a physical barrier to flow by introducing a fracture to the formation at a strategic location. his fracture is then filled with a conformance fluid and eventually becomes impermeable. The effectiveness of the proposed technique in increasing the recovery of waterfloods was investigated. A sensitivity analysis was then performed on the effects of various factors on the performance of the proposed technique. It is shown that implementing the proposed method can improve ultimate oil recovery mainly by delaying the breakthrough.