PRACTICE AND COGNITION OF INCREASING WATER SHUTOFF EFFECT IN HIGH WATER CUT STAGE IN WENMINGZAI OILFIELD

Wenmingzai Oilfield is a very complex fault block. In the high water cut stage, the problems become seriously year by year by the effect of geologic structure and long stage water flooding producing. This paper analyzes the main problem of the high water cut stage. It include more difficult water locating in performance by the effect of structure, severity interlayer interference because of the longer producing well sect, more accidents in the water shutoff job and shorter effect stage in the chemical plugging by negative pressure. The modus operandi and successful experiment for improving water shutoff efficiency was introduced since 1999. The field implement effect was evaluated.