Abstract: The oil fields in block 1/2/4 in Sudan have entered into a high water cut period. This paper reviews the effectiveness and experiences from horizontal drilling process on the basis of the applicability research of horizontal well technology in block 1/2/4. It suggests that the key of adopting horizontal well to development of the high water cut reservoir is in clear recognition of its remaining oil distribution. For the heavy oil and bottom water reservoir and the top poor oil layer of positive rhythm reservoir are more suitable for recovery by horizontal drilling process. During the development process, the position and length of horizontal well interval in the reservoirs should be designed reasonably, at the same time, the research of the water monitoring and controlling treatment should be strengthened. These practical experiences will be as a reference to the horizontal well application in high water cut oil field.

Key words: Sudan, reservoir engineering, horizontal well technology, application performance