The Study On Oil Well Water Shutoff Of Lamadian Oilfield At Ultra-high Water Cut Stage

Fluvial sandbody sediment covers a large area in Lamadian Oilfield. Reserve of crude oil in thick reservoir with the thickness of two meters and more than two meters is 5.50×108t,taking 67.51 % of the whole reserve. Coring data shows that the portion that has not been washed is 31.4 %, and the recovery rate is only 31.5 %. The present situation is that general water cut is higher than 95 % and washing between layers is seriously unbalanced.Confronting with the situation of serious heterogeneity and low and futile cycle in the thick reservoir of S.P. of Saertu in Lamadian Oilfield, this paper carried out research on recognizing futile cycle and experiments of comprehensive treatment. Based on the through understanding of regional structure and reservoir sedimentary characteristics in Lamadian Oilfield, the author carried out detailed and systematic research on futile cycle in the experiment reservoir with the help of many methods. The paper makes clear conditions, rules, and distribution characteristics of how the futile cycle forms in the extra-high water cut stage and develops ways of recognizing futile cycle in this stage. Meanwhile, the method of water plugging has also been set up and it is of great prospect since it has gained benefits in its application.The research results of this paper are as following:...