Selective ultrasonic treatment of perforation zones in horizontal oil wells for water cut reduction

Abstract A technique for treatment of perforation zones of horizontal oil wells for water cut reduction based on selective ultrasonic treatment was suggested. The technique involves online geophysical studies of horizontal wells, determination of treatment intervals based on these studies, selective ultrasonic treatment of the chosen interval and subsequent pump-out using a specially designed jet pump. The technology does not involve reduction of the flow in the well. The developed innovative technique of water cut reduction using selective ultrasonic treatment is studied within this article. Theoretical estimations and computer modeling revealed that the position of the downhole ultrasonic tool near the sidewall of the well leads to more homogeneous distribution of the induced acoustical field and wider penetration of the acoustical waves. The developed method was tested on a horizontal well in Western Siberia, which was characterized by high water cut. Based on geophysical studies only zones with low water and high oil production were treated, this lead to a decrease of the water cut by 20% and an increase of oil production by 91% after treatment of the test well.