Performance evaluation of nitrogen-assisted steam flooding process in heavy oil reservoir via numerical simulation

Abstract In this study, numerical simulation studies have been conducted to enhance oil production in X1 heavy oil reservoir using nitrogen-assisted steam injection processes. Five types of nitrogen-assisted steam flooding methods—steam flooding, steam flooding coupled with continuous nitrogen injection, coupled with intermittent nitrogen injection, coupled with nitrogen slug injection, and nitrogen flooding—have been carried out to investigate the effect of nitrogen-assisted steam flooding method on production performance. In numerical simulation study, the STARS module is applied to implement history-matching of production data, and good agreement has been achieved. Next, the orthogonal design principle is adopted to optimize the scheme of nitrogen-assisted steam flooding. The results show that steam flooding assisted by intermittent nitrogen injection is the most suitable method. In the end, the plan of nitrogen-assisted steam flooding of X1 reservoir has been designed and the oil production rate in the next 5 years has been predicted.