Model-based life cycle control of ICVs in injectors in a benchmark analogous to a pre-salt field

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Some fields in the Brazilian pre-salt feature light oil and high gas/CO2 content, which is a bottleneck to oil production due to gas processing restrictions in the facilities. To deal with this, Water-alternate-gas (WAG) is used as a recovery mechanism while the use of Interval Control Valves (ICVs) is also recommended, since these enable controlling the production or injection through segments in the wells.In this context of high gas production and WAG, a good injection management is crucial and the use of ICVs in the injection wells can help to improve the oil production and the field's economic return. In this work, we propose and compare four approaches (A, B, C, and D) to control the ICVs of the injectors considering numerical simulation and Net present value (NPV) as objective function. Approaches A and B use streamlines to correlate producers and injectors, and they also use the Gas-oil ratio (GOR) of the producers as a monitoring variable to close the valves of the injectors. The difference between them is that, in Approach A, the valves remain closed during the entire field's life cycle, while there is an alternation of each opened or closed valve for every WAG cycle in Approach B. In Approach C, the alternation between each valve is made since the beginning of the WAG cycles, instead of waiting for a trigger to start closing the valves. These three approaches are sub-divided into other (minor) approaches, depending on whether the valve remains closed, or not, during the water injection cycles. Finally, in Approach D, we attempt to control the cumulative fluid injection between the zones of the injectors. The study is applied to the SEC1_2022 benchmark case, a synthetic model analogous to a pre-salt field. Finally, we apply the best approach found to a reference case (“true response”) to assess how the proposed strategy would behave in real cases.The results indicate that closing the valves in earlier stages of the field's life cycle is better than using GOR as a trigger. Furthermore, the alternation between opened and closed valves proved to be the best way to control the valves in this case. Approach D was the best among those evaluated, with the highest increase in oil production and greatest decrease in water production, providing highest NPV. Although the platform remained constrained by gas production, this approach provided a better fluid distribution in the field and among wells, improving both oil recovery and economic returns.