Recently, modern streamline simulation has been extended to polymer flooding. In this work, we extended the applicability of streamline simulation further to efficiently manage polymer injection projects. We first present our methodology and then demonstrate the applicability of our approach using a Romanian field as an example. Owing to the price of polymers, an optimised injection strategy is crucial to minimise costs, maximize sweep, and thereby ensure profitability of a polymer flood.
The biggest advantage of streamline simulation compared to traditional finite-difference modelling is that polymer floods can be optimised on a well pattern basis. By being able to plot cumulative oil produced as a function of polymer injected for an individual well pattern, underperforming patterns—injectors and associated offset producers—can easily be indentified and rates, concentration, and slug size modified to improve the local efficiency of the flood. In this paper we introduced a new metric: the polymer injection efficiency as a function of time for each pattern and show how it is central to contain costs while improving oil recovery.
We demonstrate our management methodology on a Romanian oil field that has been operating since 1961 with 21 injectors and 136 producers. We show that the utility factor (mass of polymers injected per volume of incremental oil produced) can be reduced while sustaining oil recovery. We conclude with a discussion on streamline simulation as an enabling technology for reservoir management decisions for polymer floods and floods in general.