EVOLUTION OF PRODUCTION PRACTICE AND RESERVOIR MANAGEMENT OF THE WINTER FIELD

Actual production data of Winter Field were examined for production ra tes, oil cut, cumulative oil produced and reserves per well in relatio n to well length. The log oil cut vs. cumulative oil production per we ll of groups of wells plots showed that the reserves at a 2% oil cut w as the same despite the different lengths of these wells. Published da ta were next examined to establish the relationship between well lengt h and reserves. It is obvious that the relation between reserves as a function of well length is not a linear relationship for the entire we ll length examined. This relation shows that as the well length increa ses from 200 m to roughly 500 m there is a linear increase in reserves . The slope of the line is less than one (0.7); as the length increase s beyond 600 m there is very little increase in the reserves. This cou ld explain why the Winter wells all have the same reserves. These grou ps of wells varied in length from 574 m to 1,110 m; that is, they are all in the length range (greater than 500 m) that gives the maximum re serves((1)). In order to verify this conclusion and utilize it to incr ease the reserve from existing and future wells a series of well worko vers and treatment programs were carried out. Newly drilled wells were completed in such a way as to use the conclusions and recommendations of these programs.