Technique of Controlling Water Cut and Increasing Oil Production by Injecting Nitrogen Foam in Thick Reservoirs in Later High Water Cut Stage

Producing remaining oil on top part of thick reservoir is one of the main targets in later high water cut stage of oil field. Nitrogen foam has effect of selective plugging in high water cut layers and high permeable zones and can improve displacement efficiency, so it can be injected into thick reservoirs to control water channeling and produce remaining oil in them. Through lab experiments, foam agent which is adaptable for geologic condition of tested area is studied and field test is performed in 1 well. Oil production is increased by 2286t, and water cut decreases by 1.6%.