Many strategies have been implemented to mitigate the problem of high water-production rates seen in mature fields. One of these is the cyclic-production scheme (CPS). This strategy, which requires alternately shutting and flowing wells with high water cut over a predetermined time, enhances sweep efficiency and pressure maintenance and reduces water-handling costs. In a reservoir-simulation model of a mature oil field evaluating a total of 93 wells, simulation runs involving several scenarios showed significant advantage in applying a CPS.

Introduction

Water management has become a key strategy in fields that have entered a high-water-cut development period. As fields mature, there is a natural tendency for water volumes to increase as aquifer and injected water advances toward the producers. Furthermore, increasing levels of water production can impair oil-production rates, in some cases to the point at which the well ceases to be economical to produce. Although injected water is an enabler for improved hydrocarbon recovery, it is essential to control water-production volumes and the flood front. High water production may limit oil production in a rate-limited well, increasing water-treatment and -disposal costs.